docs: enhance 5 thin commands and add Rust API example

Commands enhanced with multi-language support, error recovery strategies,
and structured step-by-step workflows:
- build-fix: build system detection table, fix loop, recovery strategies
- test-coverage: framework detection, test generation rules, before/after report
- refactor-clean: safety tiers (SAFE/CAUTION/DANGER), multi-language tools
- update-codemaps: codemap format spec, diff detection, metadata headers
- update-docs: source-of-truth mapping, staleness checks, generated markers

New example:
- rust-api-CLAUDE.md: Axum + SQLx + PostgreSQL with layered architecture,
  thiserror patterns, compile-time SQL verification, integration test examples

commands/update-docs.md

@@ -1,31 +1,84 @@
 # Update Documentation
 
-Sync documentation from source-of-truth:
+Sync documentation with the codebase, generating from source-of-truth files.
 
-1. Read package.json scripts section
-   - Generate scripts reference table
-   - Include descriptions from comments
+## Step 1: Identify Sources of Truth
 
-2. Read .env.example
-   - Extract all environment variables
-   - Document purpose and format
+| Source | Generates |
+|--------|-----------|
+| `package.json` scripts | Available commands reference |
+| `.env.example` | Environment variable documentation |
+| `openapi.yaml` / route files | API endpoint reference |
+| Source code exports | Public API documentation |
+| `Dockerfile` / `docker-compose.yml` | Infrastructure setup docs |
 
-3. Generate docs/CONTRIB.md with:
-   - Development workflow
-   - Available scripts
-   - Environment setup
-   - Testing procedures
+## Step 2: Generate Script Reference
 
-4. Generate docs/RUNBOOK.md with:
-   - Deployment procedures
-   - Monitoring and alerts
-   - Common issues and fixes
-   - Rollback procedures
+1. Read `package.json` (or `Makefile`, `Cargo.toml`, `pyproject.toml`)
+2. Extract all scripts/commands with their descriptions
+3. Generate a reference table:
 
-5. Identify obsolete documentation:
-   - Find docs not modified in 90+ days
-   - List for manual review
+```markdown
+| Command | Description |
+|---------|-------------|
+| `npm run dev` | Start development server with hot reload |
+| `npm run build` | Production build with type checking |
+| `npm test` | Run test suite with coverage |
+```
 
-6. Show diff summary
+## Step 3: Generate Environment Documentation
 
-Single source of truth: package.json and .env.example
+1. Read `.env.example` (or `.env.template`, `.env.sample`)
+2. Extract all variables with their purposes
+3. Categorize as required vs optional
+4. Document expected format and valid values
+
+```markdown
+| Variable | Required | Description | Example |
+|----------|----------|-------------|---------|
+| `DATABASE_URL` | Yes | PostgreSQL connection string | `postgres://user:pass@host:5432/db` |
+| `LOG_LEVEL` | No | Logging verbosity (default: info) | `debug`, `info`, `warn`, `error` |
+```
+
+## Step 4: Update Contributing Guide
+
+Generate or update `docs/CONTRIBUTING.md` with:
+- Development environment setup (prerequisites, install steps)
+- Available scripts and their purposes
+- Testing procedures (how to run, how to write new tests)
+- Code style enforcement (linter, formatter, pre-commit hooks)
+- PR submission checklist
+
+## Step 5: Update Runbook
+
+Generate or update `docs/RUNBOOK.md` with:
+- Deployment procedures (step-by-step)
+- Health check endpoints and monitoring
+- Common issues and their fixes
+- Rollback procedures
+- Alerting and escalation paths
+
+## Step 6: Staleness Check
+
+1. Find documentation files not modified in 90+ days
+2. Cross-reference with recent source code changes
+3. Flag potentially outdated docs for manual review
+
+## Step 7: Show Summary
+
+```
+Documentation Update
+──────────────────────────────
+Updated:  docs/CONTRIBUTING.md (scripts table)
+Updated:  docs/ENV.md (3 new variables)
+Flagged:  docs/DEPLOY.md (142 days stale)
+Skipped:  docs/API.md (no changes detected)
+──────────────────────────────
+```
+
+## Rules
+
+- **Single source of truth**: Always generate from code, never manually edit generated sections
+- **Preserve manual sections**: Only update generated sections; leave hand-written prose intact
+- **Mark generated content**: Use `<!-- AUTO-GENERATED -->` markers around generated sections
+- **Don't create docs unprompted**: Only create new doc files if the command explicitly requests it