diff --git a/README.md b/README.md
index 98f8683e2..e13ad62e5 100644
--- a/README.md
+++ b/README.md
@@ -14,10 +14,6 @@
 
 **Stop typing code. Start directing AI agents.**
 
-> **[!WARNING]**
->
-> **This project is no longer actively maintained.** The codebase is provided as-is. No bug fixes, security updates, or new features are being developed.
-
 <details open>
 <summary><h2>Table of Contents</h2></summary>
 
diff --git a/apps/server/eslint.config.mjs b/apps/server/eslint.config.mjs
new file mode 100644
index 000000000..008c1f68e
--- /dev/null
+++ b/apps/server/eslint.config.mjs
@@ -0,0 +1,74 @@
+import { defineConfig, globalIgnores } from 'eslint/config';
+import js from '@eslint/js';
+import ts from '@typescript-eslint/eslint-plugin';
+import tsParser from '@typescript-eslint/parser';
+
+const eslintConfig = defineConfig([
+  js.configs.recommended,
+  {
+    files: ['**/*.ts'],
+    languageOptions: {
+      parser: tsParser,
+      parserOptions: {
+        ecmaVersion: 'latest',
+        sourceType: 'module',
+      },
+      globals: {
+        // Node.js globals
+        console: 'readonly',
+        process: 'readonly',
+        Buffer: 'readonly',
+        __dirname: 'readonly',
+        __filename: 'readonly',
+        URL: 'readonly',
+        URLSearchParams: 'readonly',
+        AbortController: 'readonly',
+        AbortSignal: 'readonly',
+        fetch: 'readonly',
+        Response: 'readonly',
+        Request: 'readonly',
+        Headers: 'readonly',
+        FormData: 'readonly',
+        RequestInit: 'readonly',
+        // Timers
+        setTimeout: 'readonly',
+        setInterval: 'readonly',
+        clearTimeout: 'readonly',
+        clearInterval: 'readonly',
+        setImmediate: 'readonly',
+        clearImmediate: 'readonly',
+        queueMicrotask: 'readonly',
+        // Node.js types
+        NodeJS: 'readonly',
+      },
+    },
+    plugins: {
+      '@typescript-eslint': ts,
+    },
+    rules: {
+      ...ts.configs.recommended.rules,
+      '@typescript-eslint/no-unused-vars': [
+        'warn',
+        {
+          argsIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+          caughtErrorsIgnorePattern: '^_',
+          ignoreRestSiblings: true,
+        },
+      ],
+      '@typescript-eslint/no-explicit-any': 'warn',
+      // Server code frequently works with terminal output containing ANSI escape codes
+      'no-control-regex': 'off',
+      '@typescript-eslint/ban-ts-comment': [
+        'error',
+        {
+          'ts-nocheck': 'allow-with-description',
+          minimumDescriptionLength: 10,
+        },
+      ],
+    },
+  },
+  globalIgnores(['dist/**', 'node_modules/**']),
+]);
+
+export default eslintConfig;
diff --git a/apps/server/src/routes/features/routes/create.ts b/apps/server/src/routes/features/routes/create.ts
index 29f7d0755..c607e72e4 100644
--- a/apps/server/src/routes/features/routes/create.ts
+++ b/apps/server/src/routes/features/routes/create.ts
@@ -24,19 +24,6 @@ export function createCreateHandler(featureLoader: FeatureLoader, events?: Event
         return;
       }
 
-      // Check for duplicate title if title is provided
-      if (feature.title && feature.title.trim()) {
-        const duplicate = await featureLoader.findDuplicateTitle(projectPath, feature.title);
-        if (duplicate) {
-          res.status(409).json({
-            success: false,
-            error: `A feature with title "${feature.title}" already exists`,
-            duplicateFeatureId: duplicate.id,
-          });
-          return;
-        }
-      }
-
       const created = await featureLoader.create(projectPath, feature);
 
       // Emit feature_created event for hooks
diff --git a/apps/server/src/routes/features/routes/update.ts b/apps/server/src/routes/features/routes/update.ts
index a5b532c1d..4d5e7a00e 100644
--- a/apps/server/src/routes/features/routes/update.ts
+++ b/apps/server/src/routes/features/routes/update.ts
@@ -40,23 +40,6 @@ export function createUpdateHandler(featureLoader: FeatureLoader) {
         return;
       }
 
-      // Check for duplicate title if title is being updated
-      if (updates.title && updates.title.trim()) {
-        const duplicate = await featureLoader.findDuplicateTitle(
-          projectPath,
-          updates.title,
-          featureId // Exclude the current feature from duplicate check
-        );
-        if (duplicate) {
-          res.status(409).json({
-            success: false,
-            error: `A feature with title "${updates.title}" already exists`,
-            duplicateFeatureId: duplicate.id,
-          });
-          return;
-        }
-      }
-
       // Get the current feature to detect status changes
       const currentFeature = await featureLoader.get(projectPath, featureId);
       const previousStatus = currentFeature?.status as FeatureStatus | undefined;
diff --git a/apps/server/src/routes/worktree/index.ts b/apps/server/src/routes/worktree/index.ts
index 992a7b48d..a7df37bb3 100644
--- a/apps/server/src/routes/worktree/index.ts
+++ b/apps/server/src/routes/worktree/index.ts
@@ -101,7 +101,12 @@ export function createWorktreeRoutes(
     requireValidWorktree,
     createPullHandler()
   );
-  router.post('/checkout-branch', requireValidWorktree, createCheckoutBranchHandler());
+  router.post(
+    '/checkout-branch',
+    validatePathParams('worktreePath'),
+    requireValidWorktree,
+    createCheckoutBranchHandler()
+  );
   router.post(
     '/list-branches',
     validatePathParams('worktreePath'),
diff --git a/apps/server/src/routes/worktree/routes/checkout-branch.ts b/apps/server/src/routes/worktree/routes/checkout-branch.ts
index ffa6e5e32..239634801 100644
--- a/apps/server/src/routes/worktree/routes/checkout-branch.ts
+++ b/apps/server/src/routes/worktree/routes/checkout-branch.ts
@@ -2,15 +2,15 @@
  * POST /checkout-branch endpoint - Create and checkout a new branch
  *
  * Note: Git repository validation (isGitRepo, hasCommits) is handled by
- * the requireValidWorktree middleware in index.ts
+ * the requireValidWorktree middleware in index.ts.
+ * Path validation (ALLOWED_ROOT_DIRECTORY) is handled by validatePathParams
+ * middleware in index.ts.
  */
 
 import type { Request, Response } from 'express';
-import { exec } from 'child_process';
-import { promisify } from 'util';
-import { getErrorMessage, logError } from '../common.js';
-
-const execAsync = promisify(exec);
+import path from 'path';
+import { stat } from 'fs/promises';
+import { getErrorMessage, logError, isValidBranchName, execGitCommand } from '../common.js';
 
 export function createCheckoutBranchHandler() {
   return async (req: Request, res: Response): Promise<void> => {
@@ -36,27 +36,47 @@ export function createCheckoutBranchHandler() {
         return;
       }
 
-      // Validate branch name (basic validation)
-      const invalidChars = /[\s~^:?*\[\\]/;
-      if (invalidChars.test(branchName)) {
+      // Validate branch name using shared allowlist: /^[a-zA-Z0-9._\-/]+$/
+      if (!isValidBranchName(branchName)) {
         res.status(400).json({
           success: false,
-          error: 'Branch name contains invalid characters',
+          error:
+            'Invalid branch name. Must contain only letters, numbers, dots, dashes, underscores, or slashes.',
         });
         return;
       }
 
-      // Get current branch for reference
-      const { stdout: currentBranchOutput } = await execAsync('git rev-parse --abbrev-ref HEAD', {
-        cwd: worktreePath,
-      });
+      // Resolve and validate worktreePath to prevent traversal attacks.
+      // The validatePathParams middleware checks against ALLOWED_ROOT_DIRECTORY,
+      // but we also resolve the path and verify it exists as a directory.
+      const resolvedPath = path.resolve(worktreePath);
+      try {
+        const stats = await stat(resolvedPath);
+        if (!stats.isDirectory()) {
+          res.status(400).json({
+            success: false,
+            error: 'worktreePath is not a directory',
+          });
+          return;
+        }
+      } catch {
+        res.status(400).json({
+          success: false,
+          error: 'worktreePath does not exist or is not accessible',
+        });
+        return;
+      }
+
+      // Get current branch for reference (using argument array to avoid shell injection)
+      const currentBranchOutput = await execGitCommand(
+        ['rev-parse', '--abbrev-ref', 'HEAD'],
+        resolvedPath
+      );
       const currentBranch = currentBranchOutput.trim();
 
       // Check if branch already exists
       try {
-        await execAsync(`git rev-parse --verify ${branchName}`, {
-          cwd: worktreePath,
-        });
+        await execGitCommand(['rev-parse', '--verify', branchName], resolvedPath);
         // Branch exists
         res.status(400).json({
           success: false,
@@ -67,10 +87,8 @@ export function createCheckoutBranchHandler() {
         // Branch doesn't exist, good to create
       }
 
-      // Create and checkout the new branch
-      await execAsync(`git checkout -b ${branchName}`, {
-        cwd: worktreePath,
-      });
+      // Create and checkout the new branch (using argument array to avoid shell injection)
+      await execGitCommand(['checkout', '-b', branchName], resolvedPath);
 
       res.json({
         success: true,
diff --git a/apps/server/src/routes/worktree/routes/open-in-editor.ts b/apps/server/src/routes/worktree/routes/open-in-editor.ts
index c5ea6f9eb..f0d620d4c 100644
--- a/apps/server/src/routes/worktree/routes/open-in-editor.ts
+++ b/apps/server/src/routes/worktree/routes/open-in-editor.ts
@@ -125,19 +125,14 @@ export function createOpenInEditorHandler() {
           `Failed to open in editor, falling back to file manager: ${getErrorMessage(editorError)}`
         );
 
-        try {
-          const result = await openInFileManager(worktreePath);
-          res.json({
-            success: true,
-            result: {
-              message: `Opened ${worktreePath} in ${result.editorName}`,
-              editorName: result.editorName,
-            },
-          });
-        } catch (fallbackError) {
-          // Both editor and file manager failed
-          throw fallbackError;
-        }
+        const result = await openInFileManager(worktreePath);
+        res.json({
+          success: true,
+          result: {
+            message: `Opened ${worktreePath} in ${result.editorName}`,
+            editorName: result.editorName,
+          },
+        });
       }
     } catch (error) {
       logError(error, 'Open in editor failed');
diff --git a/apps/server/src/services/claude-usage-service.ts b/apps/server/src/services/claude-usage-service.ts
index 6438b5dc4..40cffd7f7 100644
--- a/apps/server/src/services/claude-usage-service.ts
+++ b/apps/server/src/services/claude-usage-service.ts
@@ -662,7 +662,7 @@ export class ClaudeUsageService {
 
       resetTime = this.parseResetTime(resetText, type);
       // Strip timezone like "(Asia/Dubai)" from the display text
-      resetText = resetText.replace(/\s*\([A-Za-z_\/]+\)\s*$/, '').trim();
+      resetText = resetText.replace(/\s*\([A-Za-z_/]+\)\s*$/, '').trim();
     }
 
     return { percentage: percentage ?? 0, resetTime, resetText };
diff --git a/apps/server/src/services/dev-server-service.ts b/apps/server/src/services/dev-server-service.ts
index d81e539c3..76cf31748 100644
--- a/apps/server/src/services/dev-server-service.ts
+++ b/apps/server/src/services/dev-server-service.ts
@@ -124,7 +124,7 @@ class DevServerService {
       /(?:Local|Network):\s+(https?:\/\/[^\s]+)/i, // Vite format
       /(?:ready|started server).*?(?:url:\s*)?(https?:\/\/[^\s,]+)/i, // Next.js format
       /(https?:\/\/(?:localhost|127\.0\.0\.1|\[::\]):\d+)/i, // Generic localhost URL
-      /(https?:\/\/[^\s<>"{}|\\^`\[\]]+)/i, // Any HTTP(S) URL
+      /(https?:\/\/[^\s<>"{}|\\^`[\]]+)/i, // Any HTTP(S) URL
     ];
 
     for (const pattern of urlPatterns) {
diff --git a/apps/server/src/services/ideation-service.ts b/apps/server/src/services/ideation-service.ts
index efa328022..0d43252fb 100644
--- a/apps/server/src/services/ideation-service.ts
+++ b/apps/server/src/services/ideation-service.ts
@@ -888,7 +888,7 @@ ${contextSection}${existingWorkSection}`;
 
     for (const line of lines) {
       // Check for numbered items or markdown headers
-      const titleMatch = line.match(/^(?:\d+[\.\)]\s*\*{0,2}|#{1,3}\s+)(.+)/);
+      const titleMatch = line.match(/^(?:\d+[.)]\s*\*{0,2}|#{1,3}\s+)(.+)/);
 
       if (titleMatch) {
         // Save previous suggestion
diff --git a/apps/ui/eslint.config.mjs b/apps/ui/eslint.config.mjs
index 3ad4d79d5..2400404fe 100644
--- a/apps/ui/eslint.config.mjs
+++ b/apps/ui/eslint.config.mjs
@@ -119,7 +119,15 @@ const eslintConfig = defineConfig([
     },
     rules: {
       ...ts.configs.recommended.rules,
-      '@typescript-eslint/no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+      '@typescript-eslint/no-unused-vars': [
+        'warn',
+        {
+          argsIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+          caughtErrorsIgnorePattern: '^_',
+          ignoreRestSiblings: true,
+        },
+      ],
       '@typescript-eslint/no-explicit-any': 'warn',
       '@typescript-eslint/ban-ts-comment': [
         'error',
diff --git a/apps/ui/src/components/views/board-view.tsx b/apps/ui/src/components/views/board-view.tsx
index a1e1fcecd..768b40a50 100644
--- a/apps/ui/src/components/views/board-view.tsx
+++ b/apps/ui/src/components/views/board-view.tsx
@@ -590,6 +590,7 @@ export function BoardView() {
     handleForceStopFeature,
     handleStartNextFeatures,
     handleArchiveAllVerified,
+    handleDuplicateFeature,
   } = useBoardActions({
     currentProject,
     features: hookFeatures,
@@ -1503,6 +1504,8 @@ export function BoardView() {
                   setSpawnParentFeature(feature);
                   setShowAddDialog(true);
                 },
+                onDuplicate: (feature) => handleDuplicateFeature(feature, false),
+                onDuplicateAsChild: (feature) => handleDuplicateFeature(feature, true),
               }}
               runningAutoTasks={runningAutoTasksAllWorktrees}
               pipelineConfig={pipelineConfig}
@@ -1542,6 +1545,8 @@ export function BoardView() {
                 setSpawnParentFeature(feature);
                 setShowAddDialog(true);
               }}
+              onDuplicate={(feature) => handleDuplicateFeature(feature, false)}
+              onDuplicateAsChild={(feature) => handleDuplicateFeature(feature, true)}
               featuresWithContext={featuresWithContext}
               runningAutoTasks={runningAutoTasksAllWorktrees}
               onArchiveAllVerified={() => setShowArchiveAllVerifiedDialog(true)}
diff --git a/apps/ui/src/components/views/board-view/components/kanban-card/card-header.tsx b/apps/ui/src/components/views/board-view/components/kanban-card/card-header.tsx
index cc97b202c..ac80d7ed3 100644
--- a/apps/ui/src/components/views/board-view/components/kanban-card/card-header.tsx
+++ b/apps/ui/src/components/views/board-view/components/kanban-card/card-header.tsx
@@ -1,4 +1,3 @@
-// @ts-nocheck - header component props with optional handlers and status variants
 import { memo, useState } from 'react';
 import type { DraggableAttributes, DraggableSyntheticListeners } from '@dnd-kit/core';
 import { Feature } from '@/store/app-store';
@@ -9,6 +8,9 @@ import {
   DropdownMenu,
   DropdownMenuContent,
   DropdownMenuItem,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu';
 import {
@@ -20,6 +22,7 @@ import {
   ChevronDown,
   ChevronUp,
   GitFork,
+  Copy,
 } from 'lucide-react';
 import { Spinner } from '@/components/ui/spinner';
 import { CountUpTimer } from '@/components/ui/count-up-timer';
@@ -27,6 +30,65 @@ import { formatModelName, DEFAULT_MODEL } from '@/lib/agent-context-parser';
 import { DeleteConfirmDialog } from '@/components/ui/delete-confirm-dialog';
 import { getProviderIconForModel } from '@/components/ui/provider-icon';
 
+function DuplicateMenuItems({
+  onDuplicate,
+  onDuplicateAsChild,
+}: {
+  onDuplicate?: () => void;
+  onDuplicateAsChild?: () => void;
+}) {
+  if (!onDuplicate) return null;
+
+  // When there's no sub-child action, render a simple menu item (no DropdownMenuSub wrapper)
+  if (!onDuplicateAsChild) {
+    return (
+      <DropdownMenuItem
+        onClick={(e) => {
+          e.stopPropagation();
+          onDuplicate();
+        }}
+        className="text-xs"
+      >
+        <Copy className="w-3 h-3 mr-2" />
+        Duplicate
+      </DropdownMenuItem>
+    );
+  }
+
+  // When sub-child action is available, render a proper DropdownMenuSub with
+  // DropdownMenuSubTrigger and DropdownMenuSubContent per Radix conventions
+  return (
+    <DropdownMenuSub>
+      <DropdownMenuSubTrigger className="text-xs">
+        <Copy className="w-3 h-3 mr-2" />
+        Duplicate
+      </DropdownMenuSubTrigger>
+      <DropdownMenuSubContent>
+        <DropdownMenuItem
+          onClick={(e) => {
+            e.stopPropagation();
+            onDuplicate();
+          }}
+          className="text-xs"
+        >
+          <Copy className="w-3 h-3 mr-2" />
+          Duplicate
+        </DropdownMenuItem>
+        <DropdownMenuItem
+          onClick={(e) => {
+            e.stopPropagation();
+            onDuplicateAsChild();
+          }}
+          className="text-xs"
+        >
+          <GitFork className="w-3 h-3 mr-2" />
+          Duplicate as Child
+        </DropdownMenuItem>
+      </DropdownMenuSubContent>
+    </DropdownMenuSub>
+  );
+}
+
 interface CardHeaderProps {
   feature: Feature;
   isDraggable: boolean;
@@ -36,6 +98,8 @@ interface CardHeaderProps {
   onDelete: () => void;
   onViewOutput?: () => void;
   onSpawnTask?: () => void;
+  onDuplicate?: () => void;
+  onDuplicateAsChild?: () => void;
   dragHandleListeners?: DraggableSyntheticListeners;
   dragHandleAttributes?: DraggableAttributes;
 }
@@ -49,6 +113,8 @@ export const CardHeaderSection = memo(function CardHeaderSection({
   onDelete,
   onViewOutput,
   onSpawnTask,
+  onDuplicate,
+  onDuplicateAsChild,
   dragHandleListeners,
   dragHandleAttributes,
 }: CardHeaderProps) {
@@ -71,7 +137,7 @@ export const CardHeaderSection = memo(function CardHeaderSection({
         <div className="absolute top-2 right-2 flex items-center gap-1">
           <div className="flex items-center justify-center gap-2 bg-[var(--status-in-progress)]/15 border border-[var(--status-in-progress)]/50 rounded-md px-2 py-0.5">
             <Spinner size="xs" />
-            {feature.startedAt && (
+            {typeof feature.startedAt === 'string' && (
               <CountUpTimer
                 startedAt={feature.startedAt}
                 className="text-[var(--status-in-progress)] text-[10px]"
@@ -114,6 +180,10 @@ export const CardHeaderSection = memo(function CardHeaderSection({
                 <GitFork className="w-3 h-3 mr-2" />
                 Spawn Sub-Task
               </DropdownMenuItem>
+              <DuplicateMenuItems
+                onDuplicate={onDuplicate}
+                onDuplicateAsChild={onDuplicateAsChild}
+              />
               {/* Model info in dropdown */}
               {(() => {
                 const ProviderIcon = getProviderIconForModel(feature.model);
@@ -162,6 +232,29 @@ export const CardHeaderSection = memo(function CardHeaderSection({
             >
               <Trash2 className="w-4 h-4" />
             </Button>
+            {/* Only render overflow menu when there are actionable items */}
+            {onDuplicate && (
+              <DropdownMenu>
+                <DropdownMenuTrigger asChild>
+                  <Button
+                    variant="ghost"
+                    size="sm"
+                    className="h-6 w-6 p-0 hover:bg-muted/80 rounded-md"
+                    onClick={(e) => e.stopPropagation()}
+                    onPointerDown={(e) => e.stopPropagation()}
+                    data-testid={`menu-backlog-${feature.id}`}
+                  >
+                    <MoreVertical className="w-3.5 h-3.5 text-muted-foreground" />
+                  </Button>
+                </DropdownMenuTrigger>
+                <DropdownMenuContent align="end" className="w-40">
+                  <DuplicateMenuItems
+                    onDuplicate={onDuplicate}
+                    onDuplicateAsChild={onDuplicateAsChild}
+                  />
+                </DropdownMenuContent>
+              </DropdownMenu>
+            )}
           </div>
         )}
 
@@ -187,22 +280,6 @@ export const CardHeaderSection = memo(function CardHeaderSection({
               >
                 <Edit className="w-4 h-4" />
               </Button>
-              <Button
-                variant="ghost"
-                size="sm"
-                className="h-6 w-6 p-0 hover:bg-white/10 text-muted-foreground hover:text-foreground"
-                onClick={(e) => {
-                  e.stopPropagation();
-                  onSpawnTask?.();
-                }}
-                onPointerDown={(e) => e.stopPropagation()}
-                data-testid={`spawn-${
-                  feature.status === 'waiting_approval' ? 'waiting' : 'verified'
-                }-${feature.id}`}
-                title="Spawn Sub-Task"
-              >
-                <GitFork className="w-4 h-4" />
-              </Button>
               {onViewOutput && (
                 <Button
                   variant="ghost"
@@ -234,6 +311,41 @@ export const CardHeaderSection = memo(function CardHeaderSection({
               >
                 <Trash2 className="w-4 h-4" />
               </Button>
+              <DropdownMenu>
+                <DropdownMenuTrigger asChild>
+                  <Button
+                    variant="ghost"
+                    size="sm"
+                    className="h-6 w-6 p-0 hover:bg-muted/80 rounded-md"
+                    onClick={(e) => e.stopPropagation()}
+                    onPointerDown={(e) => e.stopPropagation()}
+                    data-testid={`menu-${
+                      feature.status === 'waiting_approval' ? 'waiting' : 'verified'
+                    }-${feature.id}`}
+                  >
+                    <MoreVertical className="w-3.5 h-3.5 text-muted-foreground" />
+                  </Button>
+                </DropdownMenuTrigger>
+                <DropdownMenuContent align="end" className="w-40">
+                  <DropdownMenuItem
+                    onClick={(e) => {
+                      e.stopPropagation();
+                      onSpawnTask?.();
+                    }}
+                    data-testid={`spawn-${
+                      feature.status === 'waiting_approval' ? 'waiting' : 'verified'
+                    }-${feature.id}`}
+                    className="text-xs"
+                  >
+                    <GitFork className="w-3 h-3 mr-2" />
+                    Spawn Sub-Task
+                  </DropdownMenuItem>
+                  <DuplicateMenuItems
+                    onDuplicate={onDuplicate}
+                    onDuplicateAsChild={onDuplicateAsChild}
+                  />
+                </DropdownMenuContent>
+              </DropdownMenu>
             </div>
           </>
         )}
@@ -302,6 +414,10 @@ export const CardHeaderSection = memo(function CardHeaderSection({
                   <GitFork className="w-3 h-3 mr-2" />
                   Spawn Sub-Task
                 </DropdownMenuItem>
+                <DuplicateMenuItems
+                  onDuplicate={onDuplicate}
+                  onDuplicateAsChild={onDuplicateAsChild}
+                />
                 {/* Model info in dropdown */}
                 {(() => {
                   const ProviderIcon = getProviderIconForModel(feature.model);
diff --git a/apps/ui/src/components/views/board-view/components/kanban-card/kanban-card.tsx b/apps/ui/src/components/views/board-view/components/kanban-card/kanban-card.tsx
index eb44c49b5..ab109d5f1 100644
--- a/apps/ui/src/components/views/board-view/components/kanban-card/kanban-card.tsx
+++ b/apps/ui/src/components/views/board-view/components/kanban-card/kanban-card.tsx
@@ -52,6 +52,8 @@ interface KanbanCardProps {
   onViewPlan?: () => void;
   onApprovePlan?: () => void;
   onSpawnTask?: () => void;
+  onDuplicate?: () => void;
+  onDuplicateAsChild?: () => void;
   hasContext?: boolean;
   isCurrentAutoTask?: boolean;
   shortcutKey?: string;
@@ -86,6 +88,8 @@ export const KanbanCard = memo(function KanbanCard({
   onViewPlan,
   onApprovePlan,
   onSpawnTask,
+  onDuplicate,
+  onDuplicateAsChild,
   hasContext,
   isCurrentAutoTask,
   shortcutKey,
@@ -254,6 +258,8 @@ export const KanbanCard = memo(function KanbanCard({
         onDelete={onDelete}
         onViewOutput={onViewOutput}
         onSpawnTask={onSpawnTask}
+        onDuplicate={onDuplicate}
+        onDuplicateAsChild={onDuplicateAsChild}
         dragHandleListeners={isDraggable ? listeners : undefined}
         dragHandleAttributes={isDraggable ? attributes : undefined}
       />
diff --git a/apps/ui/src/components/views/board-view/components/list-view/list-view.tsx b/apps/ui/src/components/views/board-view/components/list-view/list-view.tsx
index 0a08b1270..cac687eb4 100644
--- a/apps/ui/src/components/views/board-view/components/list-view/list-view.tsx
+++ b/apps/ui/src/components/views/board-view/components/list-view/list-view.tsx
@@ -42,6 +42,8 @@ export interface ListViewActionHandlers {
   onViewPlan?: (feature: Feature) => void;
   onApprovePlan?: (feature: Feature) => void;
   onSpawnTask?: (feature: Feature) => void;
+  onDuplicate?: (feature: Feature) => void;
+  onDuplicateAsChild?: (feature: Feature) => void;
 }
 
 export interface ListViewProps {
@@ -313,6 +315,18 @@ export const ListView = memo(function ListView({
               if (f) actionHandlers.onSpawnTask?.(f);
             }
           : undefined,
+        duplicate: actionHandlers.onDuplicate
+          ? (id) => {
+              const f = allFeatures.find((f) => f.id === id);
+              if (f) actionHandlers.onDuplicate?.(f);
+            }
+          : undefined,
+        duplicateAsChild: actionHandlers.onDuplicateAsChild
+          ? (id) => {
+              const f = allFeatures.find((f) => f.id === id);
+              if (f) actionHandlers.onDuplicateAsChild?.(f);
+            }
+          : undefined,
       });
     },
     [actionHandlers, allFeatures]
diff --git a/apps/ui/src/components/views/board-view/components/list-view/row-actions.tsx b/apps/ui/src/components/views/board-view/components/list-view/row-actions.tsx
index bb5c53d16..60158d0fd 100644
--- a/apps/ui/src/components/views/board-view/components/list-view/row-actions.tsx
+++ b/apps/ui/src/components/views/board-view/components/list-view/row-actions.tsx
@@ -14,6 +14,7 @@ import {
   GitBranch,
   GitFork,
   ExternalLink,
+  Copy,
 } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { Button } from '@/components/ui/button';
@@ -22,6 +23,9 @@ import {
   DropdownMenuContent,
   DropdownMenuItem,
   DropdownMenuSeparator,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu';
 import type { Feature } from '@/store/app-store';
@@ -43,6 +47,8 @@ export interface RowActionHandlers {
   onViewPlan?: () => void;
   onApprovePlan?: () => void;
   onSpawnTask?: () => void;
+  onDuplicate?: () => void;
+  onDuplicateAsChild?: () => void;
 }
 
 export interface RowActionsProps {
@@ -405,6 +411,31 @@ export const RowActions = memo(function RowActions({
                   onClick={withClose(handlers.onSpawnTask)}
                 />
               )}
+              {handlers.onDuplicate && (
+                <DropdownMenuSub>
+                  <div className="flex items-center">
+                    <DropdownMenuItem
+                      onClick={withClose(handlers.onDuplicate)}
+                      className="flex-1 pr-0 rounded-r-none"
+                    >
+                      <Copy className="w-4 h-4 mr-2" />
+                      Duplicate
+                    </DropdownMenuItem>
+                    {handlers.onDuplicateAsChild && (
+                      <DropdownMenuSubTrigger className="px-1 rounded-l-none border-l border-border/30 h-8" />
+                    )}
+                  </div>
+                  {handlers.onDuplicateAsChild && (
+                    <DropdownMenuSubContent>
+                      <MenuItem
+                        icon={GitFork}
+                        label="Duplicate as Child"
+                        onClick={withClose(handlers.onDuplicateAsChild)}
+                      />
+                    </DropdownMenuSubContent>
+                  )}
+                </DropdownMenuSub>
+              )}
               <DropdownMenuSeparator />
               <MenuItem
                 icon={Trash2}
@@ -457,6 +488,31 @@ export const RowActions = memo(function RowActions({
                   onClick={withClose(handlers.onSpawnTask)}
                 />
               )}
+              {handlers.onDuplicate && (
+                <DropdownMenuSub>
+                  <div className="flex items-center">
+                    <DropdownMenuItem
+                      onClick={withClose(handlers.onDuplicate)}
+                      className="flex-1 pr-0 rounded-r-none"
+                    >
+                      <Copy className="w-4 h-4 mr-2" />
+                      Duplicate
+                    </DropdownMenuItem>
+                    {handlers.onDuplicateAsChild && (
+                      <DropdownMenuSubTrigger className="px-1 rounded-l-none border-l border-border/30 h-8" />
+                    )}
+                  </div>
+                  {handlers.onDuplicateAsChild && (
+                    <DropdownMenuSubContent>
+                      <MenuItem
+                        icon={GitFork}
+                        label="Duplicate as Child"
+                        onClick={withClose(handlers.onDuplicateAsChild)}
+                      />
+                    </DropdownMenuSubContent>
+                  )}
+                </DropdownMenuSub>
+              )}
               <MenuItem
                 icon={Trash2}
                 label="Delete"
@@ -503,6 +559,31 @@ export const RowActions = memo(function RowActions({
                   onClick={withClose(handlers.onSpawnTask)}
                 />
               )}
+              {handlers.onDuplicate && (
+                <DropdownMenuSub>
+                  <div className="flex items-center">
+                    <DropdownMenuItem
+                      onClick={withClose(handlers.onDuplicate)}
+                      className="flex-1 pr-0 rounded-r-none"
+                    >
+                      <Copy className="w-4 h-4 mr-2" />
+                      Duplicate
+                    </DropdownMenuItem>
+                    {handlers.onDuplicateAsChild && (
+                      <DropdownMenuSubTrigger className="px-1 rounded-l-none border-l border-border/30 h-8" />
+                    )}
+                  </div>
+                  {handlers.onDuplicateAsChild && (
+                    <DropdownMenuSubContent>
+                      <MenuItem
+                        icon={GitFork}
+                        label="Duplicate as Child"
+                        onClick={withClose(handlers.onDuplicateAsChild)}
+                      />
+                    </DropdownMenuSubContent>
+                  )}
+                </DropdownMenuSub>
+              )}
               <MenuItem
                 icon={Trash2}
                 label="Delete"
@@ -554,6 +635,31 @@ export const RowActions = memo(function RowActions({
                   onClick={withClose(handlers.onSpawnTask)}
                 />
               )}
+              {handlers.onDuplicate && (
+                <DropdownMenuSub>
+                  <div className="flex items-center">
+                    <DropdownMenuItem
+                      onClick={withClose(handlers.onDuplicate)}
+                      className="flex-1 pr-0 rounded-r-none"
+                    >
+                      <Copy className="w-4 h-4 mr-2" />
+                      Duplicate
+                    </DropdownMenuItem>
+                    {handlers.onDuplicateAsChild && (
+                      <DropdownMenuSubTrigger className="px-1 rounded-l-none border-l border-border/30 h-8" />
+                    )}
+                  </div>
+                  {handlers.onDuplicateAsChild && (
+                    <DropdownMenuSubContent>
+                      <MenuItem
+                        icon={GitFork}
+                        label="Duplicate as Child"
+                        onClick={withClose(handlers.onDuplicateAsChild)}
+                      />
+                    </DropdownMenuSubContent>
+                  )}
+                </DropdownMenuSub>
+              )}
               <MenuItem
                 icon={Trash2}
                 label="Delete"
@@ -581,6 +687,31 @@ export const RowActions = memo(function RowActions({
                   onClick={withClose(handlers.onSpawnTask)}
                 />
               )}
+              {handlers.onDuplicate && (
+                <DropdownMenuSub>
+                  <div className="flex items-center">
+                    <DropdownMenuItem
+                      onClick={withClose(handlers.onDuplicate)}
+                      className="flex-1 pr-0 rounded-r-none"
+                    >
+                      <Copy className="w-4 h-4 mr-2" />
+                      Duplicate
+                    </DropdownMenuItem>
+                    {handlers.onDuplicateAsChild && (
+                      <DropdownMenuSubTrigger className="px-1 rounded-l-none border-l border-border/30 h-8" />
+                    )}
+                  </div>
+                  {handlers.onDuplicateAsChild && (
+                    <DropdownMenuSubContent>
+                      <MenuItem
+                        icon={GitFork}
+                        label="Duplicate as Child"
+                        onClick={withClose(handlers.onDuplicateAsChild)}
+                      />
+                    </DropdownMenuSubContent>
+                  )}
+                </DropdownMenuSub>
+              )}
               <DropdownMenuSeparator />
               <MenuItem
                 icon={Trash2}
@@ -615,6 +746,8 @@ export function createRowActionHandlers(
     viewPlan?: (id: string) => void;
     approvePlan?: (id: string) => void;
     spawnTask?: (id: string) => void;
+    duplicate?: (id: string) => void;
+    duplicateAsChild?: (id: string) => void;
   }
 ): RowActionHandlers {
   return {
@@ -631,5 +764,9 @@ export function createRowActionHandlers(
     onViewPlan: actions.viewPlan ? () => actions.viewPlan!(featureId) : undefined,
     onApprovePlan: actions.approvePlan ? () => actions.approvePlan!(featureId) : undefined,
     onSpawnTask: actions.spawnTask ? () => actions.spawnTask!(featureId) : undefined,
+    onDuplicate: actions.duplicate ? () => actions.duplicate!(featureId) : undefined,
+    onDuplicateAsChild: actions.duplicateAsChild
+      ? () => actions.duplicateAsChild!(featureId)
+      : undefined,
   };
 }
diff --git a/apps/ui/src/components/views/board-view/hooks/use-board-actions.ts b/apps/ui/src/components/views/board-view/hooks/use-board-actions.ts
index aedeebaed..75d490309 100644
--- a/apps/ui/src/components/views/board-view/hooks/use-board-actions.ts
+++ b/apps/ui/src/components/views/board-view/hooks/use-board-actions.ts
@@ -517,7 +517,7 @@ export function useBoardActions({
       }
 
       removeFeature(featureId);
-      persistFeatureDelete(featureId);
+      await persistFeatureDelete(featureId);
     },
     [features, runningAutoTasks, autoMode, removeFeature, persistFeatureDelete]
   );
@@ -1090,6 +1090,38 @@ export function useBoardActions({
     });
   }, [features, runningAutoTasks, autoMode, updateFeature, persistFeatureUpdate]);
 
+  const handleDuplicateFeature = useCallback(
+    async (feature: Feature, asChild: boolean = false) => {
+      // Copy all feature data, stripping id, status (handled by create), and runtime/state fields
+      const {
+        id: _id,
+        status: _status,
+        startedAt: _startedAt,
+        error: _error,
+        summary: _summary,
+        spec: _spec,
+        passes: _passes,
+        planSpec: _planSpec,
+        descriptionHistory: _descriptionHistory,
+        titleGenerating: _titleGenerating,
+        ...featureData
+      } = feature;
+      const duplicatedFeatureData = {
+        ...featureData,
+        // If duplicating as child, set source as dependency; otherwise keep existing
+        ...(asChild && { dependencies: [feature.id] }),
+      };
+
+      // Reuse the existing handleAddFeature logic
+      await handleAddFeature(duplicatedFeatureData);
+
+      toast.success(asChild ? 'Duplicated as child' : 'Feature duplicated', {
+        description: `Created copy of: ${truncateDescription(feature.description || feature.title || '')}`,
+      });
+    },
+    [handleAddFeature]
+  );
+
   return {
     handleAddFeature,
     handleUpdateFeature,
@@ -1110,5 +1142,6 @@ export function useBoardActions({
     handleForceStopFeature,
     handleStartNextFeatures,
     handleArchiveAllVerified,
+    handleDuplicateFeature,
   };
 }
diff --git a/apps/ui/src/components/views/board-view/hooks/use-board-persistence.ts b/apps/ui/src/components/views/board-view/hooks/use-board-persistence.ts
index 48793f939..143e9c3ab 100644
--- a/apps/ui/src/components/views/board-view/hooks/use-board-persistence.ts
+++ b/apps/ui/src/components/views/board-view/hooks/use-board-persistence.ts
@@ -85,15 +85,48 @@ export function useBoardPersistence({ currentProject }: UseBoardPersistenceProps
         throw new Error('Features API not available');
       }
 
-      const result = await api.features.create(currentProject.path, feature as ApiFeature);
-      if (result.success && result.feature) {
-        updateFeature(result.feature.id, result.feature as Partial<Feature>);
-        // Invalidate React Query cache to sync UI
+      // Capture previous cache snapshot for synchronous rollback on error
+      const previousFeatures = queryClient.getQueryData<Feature[]>(
+        queryKeys.features.all(currentProject.path)
+      );
+
+      // Optimistically add to React Query cache for immediate board refresh
+      queryClient.setQueryData<Feature[]>(
+        queryKeys.features.all(currentProject.path),
+        (existing) => (existing ? [...existing, feature] : [feature])
+      );
+
+      try {
+        const result = await api.features.create(currentProject.path, feature as ApiFeature);
+        if (result.success && result.feature) {
+          updateFeature(result.feature.id, result.feature as Partial<Feature>);
+          // Update cache with server-confirmed feature before invalidating
+          queryClient.setQueryData<Feature[]>(
+            queryKeys.features.all(currentProject.path),
+            (features) => {
+              if (!features) return features;
+              return features.map((f) =>
+                f.id === result.feature!.id ? { ...f, ...(result.feature as Feature) } : f
+              );
+            }
+          );
+        } else if (!result.success) {
+          throw new Error(result.error || 'Failed to create feature on server');
+        }
+        // Always invalidate to sync with server state
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.all(currentProject.path),
+        });
+      } catch (error) {
+        logger.error('Failed to persist feature creation:', error);
+        // Rollback optimistic update synchronously on error
+        if (previousFeatures) {
+          queryClient.setQueryData(queryKeys.features.all(currentProject.path), previousFeatures);
+        }
         queryClient.invalidateQueries({
           queryKey: queryKeys.features.all(currentProject.path),
         });
-      } else if (!result.success) {
-        throw new Error(result.error || 'Failed to create feature on server');
+        throw error;
       }
     },
     [currentProject, updateFeature, queryClient]
@@ -104,20 +137,42 @@ export function useBoardPersistence({ currentProject }: UseBoardPersistenceProps
     async (featureId: string) => {
       if (!currentProject) return;
 
+      // Optimistically remove from React Query cache for immediate board refresh
+      const previousFeatures = queryClient.getQueryData<Feature[]>(
+        queryKeys.features.all(currentProject.path)
+      );
+      queryClient.setQueryData<Feature[]>(
+        queryKeys.features.all(currentProject.path),
+        (existing) => (existing ? existing.filter((f) => f.id !== featureId) : existing)
+      );
+
       try {
         const api = getElectronAPI();
         if (!api.features) {
-          logger.error('Features API not available');
-          return;
+          // Rollback optimistic deletion since we can't persist
+          if (previousFeatures) {
+            queryClient.setQueryData(queryKeys.features.all(currentProject.path), previousFeatures);
+          }
+          queryClient.invalidateQueries({
+            queryKey: queryKeys.features.all(currentProject.path),
+          });
+          throw new Error('Features API not available');
         }
 
         await api.features.delete(currentProject.path, featureId);
-        // Invalidate React Query cache to sync UI
+        // Invalidate to sync with server state
         queryClient.invalidateQueries({
           queryKey: queryKeys.features.all(currentProject.path),
         });
       } catch (error) {
         logger.error('Failed to persist feature deletion:', error);
+        // Rollback optimistic update on error
+        if (previousFeatures) {
+          queryClient.setQueryData(queryKeys.features.all(currentProject.path), previousFeatures);
+        }
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.all(currentProject.path),
+        });
       }
     },
     [currentProject, queryClient]
diff --git a/apps/ui/src/components/views/board-view/kanban-board.tsx b/apps/ui/src/components/views/board-view/kanban-board.tsx
index 7f8573923..1a84080b4 100644
--- a/apps/ui/src/components/views/board-view/kanban-board.tsx
+++ b/apps/ui/src/components/views/board-view/kanban-board.tsx
@@ -46,6 +46,8 @@ interface KanbanBoardProps {
   onViewPlan: (feature: Feature) => void;
   onApprovePlan: (feature: Feature) => void;
   onSpawnTask?: (feature: Feature) => void;
+  onDuplicate?: (feature: Feature) => void;
+  onDuplicateAsChild?: (feature: Feature) => void;
   featuresWithContext: Set<string>;
   runningAutoTasks: string[];
   onArchiveAllVerified: () => void;
@@ -282,6 +284,8 @@ export function KanbanBoard({
   onViewPlan,
   onApprovePlan,
   onSpawnTask,
+  onDuplicate,
+  onDuplicateAsChild,
   featuresWithContext,
   runningAutoTasks,
   onArchiveAllVerified,
@@ -569,6 +573,8 @@ export function KanbanBoard({
                                       onViewPlan={() => onViewPlan(feature)}
                                       onApprovePlan={() => onApprovePlan(feature)}
                                       onSpawnTask={() => onSpawnTask?.(feature)}
+                                      onDuplicate={() => onDuplicate?.(feature)}
+                                      onDuplicateAsChild={() => onDuplicateAsChild?.(feature)}
                                       hasContext={featuresWithContext.has(feature.id)}
                                       isCurrentAutoTask={runningAutoTasks.includes(feature.id)}
                                       shortcutKey={shortcutKey}
@@ -611,6 +617,8 @@ export function KanbanBoard({
                                 onViewPlan={() => onViewPlan(feature)}
                                 onApprovePlan={() => onApprovePlan(feature)}
                                 onSpawnTask={() => onSpawnTask?.(feature)}
+                                onDuplicate={() => onDuplicate?.(feature)}
+                                onDuplicateAsChild={() => onDuplicateAsChild?.(feature)}
                                 hasContext={featuresWithContext.has(feature.id)}
                                 isCurrentAutoTask={runningAutoTasks.includes(feature.id)}
                                 shortcutKey={shortcutKey}
diff --git a/apps/ui/src/components/views/spec-view/components/edit-mode/features-section.tsx b/apps/ui/src/components/views/spec-view/components/edit-mode/features-section.tsx
index b27ec3e43..ad82a4d77 100644
--- a/apps/ui/src/components/views/spec-view/components/edit-mode/features-section.tsx
+++ b/apps/ui/src/components/views/spec-view/components/edit-mode/features-section.tsx
@@ -32,7 +32,6 @@ function featureToInternal(feature: Feature): FeatureWithId {
 }
 
 function internalToFeature(internal: FeatureWithId): Feature {
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const { _id, _locationIds, ...feature } = internal;
   return feature;
 }
diff --git a/apps/ui/src/components/views/spec-view/components/edit-mode/roadmap-section.tsx b/apps/ui/src/components/views/spec-view/components/edit-mode/roadmap-section.tsx
index c5d6ddd47..b13f35e78 100644
--- a/apps/ui/src/components/views/spec-view/components/edit-mode/roadmap-section.tsx
+++ b/apps/ui/src/components/views/spec-view/components/edit-mode/roadmap-section.tsx
@@ -27,7 +27,6 @@ function phaseToInternal(phase: RoadmapPhase): PhaseWithId {
 }
 
 function internalToPhase(internal: PhaseWithId): RoadmapPhase {
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const { _id, ...phase } = internal;
   return phase;
 }
diff --git a/apps/ui/src/lib/electron.ts b/apps/ui/src/lib/electron.ts
index 22079822c..446b7b6fb 100644
--- a/apps/ui/src/lib/electron.ts
+++ b/apps/ui/src/lib/electron.ts
@@ -1062,7 +1062,6 @@ if (typeof window !== 'undefined') {
 }
 
 // Mock API for development/fallback when no backend is available
-// eslint-disable-next-line @typescript-eslint/no-unused-vars
 const _getMockElectronAPI = (): ElectronAPI => {
   return {
     ping: async () => 'pong (mock)',
diff --git a/apps/ui/src/store/test-runners-store.ts b/apps/ui/src/store/test-runners-store.ts
index b763c15a9..8f8f79843 100644
--- a/apps/ui/src/store/test-runners-store.ts
+++ b/apps/ui/src/store/test-runners-store.ts
@@ -155,7 +155,6 @@ export const useTestRunnersStore = create<TestRunnersState & TestRunnersActions>
       const finishedAt = new Date().toISOString();
 
       // Remove from active sessions since it's no longer running
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       const { [session.worktreePath]: _, ...remainingActive } = state.activeSessionByWorktree;
 
       return {
@@ -202,7 +201,6 @@ export const useTestRunnersStore = create<TestRunnersState & TestRunnersActions>
       const session = state.sessions[sessionId];
       if (!session) return state;
 
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       const { [sessionId]: _, ...remainingSessions } = state.sessions;
 
       // Remove from active if this was the active session
@@ -231,7 +229,6 @@ export const useTestRunnersStore = create<TestRunnersState & TestRunnersActions>
       });
 
       // Remove from active
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       const { [worktreePath]: _, ...remainingActive } = state.activeSessionByWorktree;
 
       return {
diff --git a/libs/types/src/pipeline.ts b/libs/types/src/pipeline.ts
index 05a4b4aad..7190abbd8 100644
--- a/libs/types/src/pipeline.ts
+++ b/libs/types/src/pipeline.ts
@@ -21,6 +21,7 @@ export type PipelineStatus = `pipeline_${string}`;
 
 export type FeatureStatusWithPipeline =
   | 'backlog'
+  | 'ready'
   | 'in_progress'
   | 'interrupted'
   | 'waiting_approval'