feat: Add multi-model AI toolkit

.claude/agents/dev-agent.md

@@ -6,19 +6,24 @@ You are the **Development Agent**, responsible for implementing features,
 writing code, and following project patterns and best practices.
 
 ## Required Skills
+
 Load before ANY implementation:
+
 - `.claude/skills/scope-guard/SKILL.md` - Scope validation
 
 ## CRITICAL: Scope Awareness
 
 ### Before ANY Implementation
+
 1. Load scope-guard skill
 2. Check current phase from `.claude/state/execution.json`
 3. Verify ALL planned files are within phase scope
 4. If ANY file belongs to future phase → **STOP IMMEDIATELY**
 
 ### Scope Violation Response
+
 If out-of-scope work is detected:
+
 ```
 ⛔ SCOPE VIOLATION DETECTED
 
@@ -34,6 +39,7 @@ RESOLUTION: This deliverable is scheduled for Phase {{N}}.
 ```
 
 ### MCP Integration
+
 - Use **Serena** for code analysis before implementation
 - Use **Chrome DevTools** for live testing
 - Use **Context7** for framework documentation lookup

.claude/agents/orchestrator-agent.md

@@ -6,14 +6,17 @@ Central coordination agent that manages workflow execution, agent delegation,
 and system-wide state across the project lifecycle.
 
 ## Required Skills
+
 Before ANY execution, load these skills:
+
 - `.claude/skills/phase-control/SKILL.md` - Phase boundary enforcement
 - `.claude/skills/scope-guard/SKILL.md` - Scope violation prevention
 - `.claude/skills/checkpoint-manager/SKILL.md` - Checkpoint management
 
 ## CRITICAL: Scope Control Rules
 
 ### Phase Boundaries (MANDATORY - NO EXCEPTIONS)
+
 1. **NEVER** execute tasks from a phase that hasn't been explicitly authorized
 2. **NEVER** auto-generate Phase N+1 plans after completing Phase N
 3. **NEVER** continue past a phase boundary without explicit user command
@@ -22,6 +25,7 @@ Before ANY execution, load these skills:
 6. **ALWAYS** load phase-control skill before task execution
 
 ### Before EVERY Task
+
 ```
 1. Check current authorized phase from .claude/state/execution.json
 2. Verify task belongs to authorized phase

.claude/agents/planner-agent.md

@@ -169,6 +169,64 @@ Brief description of phase goals
 4. **Appropriate Granularity**: Not too broad, not too detailed
 5. **Realistic Sequencing**: Account for natural workflow
 
+## Multi-Model Support
+
+The planner agent supports cross-validation with secondary models to get
+different perspectives on architecture decisions.
+
+### Configuration
+
+See `.claude/config/models.yml`:
+
+```yaml
+agent_overrides:
+  planner:
+    primary: 'claude-sonnet-4-20250514'
+    secondary: 'gemini-2.5-pro'
+    cross_validate: true
+```
+
+### Cross-Validation Process
+
+When cross-validation is enabled:
+
+1. Primary model (Claude) generates the plan
+2. Secondary model (Gemini/GPT-4) reviews the plan
+3. Differences are highlighted for user review
+4. User makes final decisions on conflicts
+
+### When to Use Cross-Validation
+
+**Recommended for:**
+
+- Major architecture decisions
+- Database schema design
+- API structure planning
+- Security-sensitive features
+
+**Optional for:**
+
+- Simple feature planning
+- Bug fix planning
+- Documentation tasks
+
+### Disabling Cross-Validation
+
+For a single run:
+
+```
+/project-planner --no-cross-validate
+```
+
+Permanently:
+
+```yaml
+# .claude/config/models.yml
+agent_overrides:
+  planner:
+    cross_validate: false
+```
+
 ## Communication
 
 Reports to: Orchestrator agent Triggers: dev-agent, test-agent, docs-agent

.claude/agents/review-agent.md

@@ -251,3 +251,95 @@ When complete, report:
 
 ### Status: {{Complete}}
 ```
+
+## Multi-Model Cross-Validation
+
+The review agent supports cross-validation where a secondary model independently
+reviews the same code, catching issues that a single model might miss.
+
+### Configuration
+
+See `.claude/config/models.yml`:
+
+```yaml
+agent_overrides:
+  review:
+    primary: 'claude-sonnet-4-20250514'
+    secondary: 'gpt-4o'
+    cross_validate: true
+```
+
+### Cross-Validation Process
+
+When enabled:
+
+1. **Primary Review** - Claude reviews the code
+2. **Secondary Review** - GPT-4/Gemini independently reviews
+3. **Comparison** - Findings are deduplicated and merged
+4. **Conflict Highlighting** - Disagreements shown to user
+
+### Output with Cross-Validation
+
+```markdown
+## Cross-Validated Review
+
+### Primary (Claude Sonnet 4)
+
+- Found 3 issues
+- Security: ✅ Passed
+- Accessibility: ⚠️ 1 issue
+
+### Secondary (GPT-4o)
+
+- Found 4 issues
+- Security: ⚠️ 1 issue (XSS risk)
+- Accessibility: ⚠️ 2 issues
+
+### Merged Findings (deduplicated)
+
+| #   | Issue                | Found By | Severity |
+| --- | -------------------- | -------- | -------- |
+| 1   | XSS vulnerability    | GPT-4    | Critical |
+| 2   | Missing ARIA label   | Both     | Major    |
+| 3   | Focus trap missing   | GPT-4    | Major    |
+| 4   | Consider memoization | Claude   | Minor    |
+
+### Disagreements
+
+- Claude: Security passed
+- GPT-4: Found potential XSS → Human review recommended for security concern
+```
+
+### When Cross-Validation Triggers
+
+By default:
+
+- **Security-sensitive code** - Always
+- **High complexity** - When cyclomatic complexity > 10
+- **On request** - When `--cross-validate` flag used
+
+### Requesting Cross-Validation
+
+```bash
+# Single file
+/review --cross-validate src/auth.ts
+
+# Always for security
+# Configure in models.yml:
+cross_validation:
+  triggers:
+    review:
+      on_security: true
+```
+
+### Disabling Cross-Validation
+
+```bash
+# Single run
+/review --no-cross-validate src/utils.ts
+
+# Permanently - edit models.yml
+agent_overrides:
+  review:
+    cross_validate: false
+```

.claude/commands/phase-approve.md

@@ -1,24 +1,30 @@
 # /phase-approve - Authorize Next Phase
 
 ## Purpose
-Explicitly authorizes execution of the next phase. This is the ONLY way to advance beyond the current phase.
+
+Explicitly authorizes execution of the next phase. This is the ONLY way to
+advance beyond the current phase.
 
 ## Trigger
+
 ```
 /phase-approve <phase_number>
 ```
 
 ## Arguments
+
 - `phase_number` (required): The phase number to authorize (e.g., 2)
 
 ## Process
 
 ### Step 1: Validate Request
+
 1. Check that previous phase is complete
 2. Check that requested phase is next in sequence
 3. Verify no unresolved scope violations
 
 ### Step 2: Confirm with User
+
 ```
 ╔══════════════════════════════════════════════════════════════╗
 ║  📋 PHASE AUTHORIZATION REQUEST                              ║
@@ -46,7 +52,9 @@ Type "APPROVE" to authorize Phase {{N}}, or "CANCEL" to abort.
 ```
 
 ### Step 3: Update State
+
 If approved, update `.claude/state/execution.json`:
+
 ```json
 {
   "authorized_phases": [1, 2],
@@ -56,6 +64,7 @@ If approved, update `.claude/state/execution.json`:
 ```
 
 ### Step 4: Confirm Authorization
+
 ```
 ╔══════════════════════════════════════════════════════════════╗
 ║  ✓ PHASE {{N}} AUTHORIZED                                    ║
@@ -71,12 +80,14 @@ If approved, update `.claude/state/execution.json`:
 ## Validation Rules
 
 ### Cannot Approve If:
+
 - Previous phase is not complete
 - Unresolved scope violations exist
 - Pending checkpoints require approval
 - Skipping phases (e.g., approving Phase 3 when Phase 2 not done)
 
 ### Error Messages
+
 ```
 ⛔ CANNOT AUTHORIZE PHASE {{N}}
 
@@ -87,6 +98,7 @@ Complete Phase {{N-1}} first, then try again.
 ```
 
 ## Example Usage
+
 ```bash
 # After completing Phase 1
 /phase-approve 2

.claude/commands/status.md

@@ -1,9 +1,11 @@
 # /status - Execution Status Command
 
 ## Purpose
+
 Displays current execution state, phase progress, and next steps.
 
 ## Trigger
+
 Run `/status` at any time to see project state.
 
 ## Output Format
@@ -50,21 +52,22 @@ Run `/status` at any time to see project state.
 ## Data Sources
 
 Read from:
+
 1. `.claude/state/execution.json` - Execution state
 2. `.claude/tasks/phase-{{N}}-tasks.md` - Task progress
 3. `.claude/config.yml` - Configuration
 4. MCP server status check
 
 ## Status Values
 
-| Status | Meaning |
-|--------|---------|
-| `not_started` | Phase planning not yet run |
-| `planning` | Running /project-planner or /task-planner |
-| `in_progress` | Tasks being executed |
-| `awaiting_approval` | At checkpoint, waiting for user |
-| `complete` | Phase finished |
-| `blocked` | Execution halted due to error/violation |
+| Status              | Meaning                                   |
+| ------------------- | ----------------------------------------- |
+| `not_started`       | Phase planning not yet run                |
+| `planning`          | Running /project-planner or /task-planner |
+| `in_progress`       | Tasks being executed                      |
+| `awaiting_approval` | At checkpoint, waiting for user           |
+| `complete`          | Phase finished                            |
+| `blocked`           | Execution halted due to error/violation   |
 
 ## Next Steps Logic
 

.claude/commands/task-runner.md

@@ -40,6 +40,7 @@ Before ANY execution, output:
 ### Step 0.5: Load Required Skills
 
 Before execution, load:
+
 1. `.claude/skills/phase-control/SKILL.md`
 2. `.claude/skills/scope-guard/SKILL.md`
 3. `.claude/skills/checkpoint-manager/SKILL.md`
@@ -203,6 +204,7 @@ Output exactly this completion message:
 ```
 
 **CRITICAL RULES:**
+
 - **NEVER** automatically invoke task-planner for next phase
 - **NEVER** automatically invoke task-runner for next phase
 - **NEVER** generate Phase N+1 plans without explicit user command

.claude/commands/worktree-disable.md

@@ -1,17 +1,21 @@
 # /worktree-disable - Disable Git Worktree Mode
 
 ## Purpose
+
 Returns to sequential task execution. Cleans up existing worktrees.
 
 ## Trigger
+
 ```
 /worktree-disable
 ```
 
 ## Process
 
 ### Step 1: Check for Active Worktrees
+
 If worktrees exist with uncommitted work:
+
 ```
 ⚠️  ACTIVE WORKTREES DETECTED
 
@@ -26,6 +30,7 @@ Options:
 ```
 
 ### Step 2: Clean Up Worktrees
+
 ```bash
 # Remove all worktrees
 git worktree list | grep ".worktrees" | while read wt; do
@@ -37,14 +42,17 @@ git branch | grep "task/" | xargs git branch -D
 ```
 
 ### Step 3: Update Config
+
 Sets in `.claude/config.yml`:
+
 ```yaml
 git:
   worktrees:
     enabled: false
 ```
 
 ### Step 4: Confirm
+
 ```
 ╔══════════════════════════════════════════════════════════════╗
 ║  ✓ GIT WORKTREE MODE DISABLED                                ║