common/tasks: New dir, add AI-driven forge review workflow

Add a tasks directory designed primarily for AI agents to execute.
These are called "skills" in Claude Code and "commands" in OpenCode,
but they're simply structured markdown files.

The first task is perform-forge-review.md, which defines an AI-augmented
human-approved code review workflow. The key design principle is that
the AI builds a review in a local JSONL file, which the human can
inspect and edit before submission. The review is submitted as a
pending/draft review, allowing the human to make final edits in the
forge UI before publishing.

Assisted-by: OpenCode (Claude Sonnet 4)
Signed-off-by: Colin Walters <walters@verbum.org>

Author: cgwalters

common/AGENTS.md

@@ -34,6 +34,15 @@ looking for any other issues).
 If you are performing a review of other's code, the same
 principles apply.
 
+## Tasks
+
+The [agents/tasks/](agents/tasks/) directory contains reusable task definitions that you
+can execute. These are roughly equivalent to OpenCode "commands" or Claude Code
+"skills".
+
+If the user gives an instruction of the form "run task ..." or similar
+then you should read the agents/tasks/README.md file and find the relevant task and continue.
+
 ## Follow other guidelines
 
 Look at the project README.md and look for guidelines

common/agents/tasks/README.md

@@ -0,0 +1,14 @@
+# Tasks
+
+Reusable task definitions for AI agents. See [AGENTS.md](../../AGENTS.md)
+for how to execute these tasks.
+
+Each `.md` file uses YAML frontmatter (`name`, `description`) followed
+by markdown instructions — compatible with Claude Code skills and
+OpenCode commands.
+
+## Available Tasks
+
+- **[perform-forge-review](perform-forge-review.md)** — Create AI-assisted code
+  reviews on GitHub, GitLab, or Forgejo. Builds review comments in a local JSONL
+  file for human inspection before submitting as a pending/draft review.