phxdocument

# Document Generate documentation for newly implemented features. ## Usage ``` /phx:document .claude/plans/magic-link-auth/plan.md /phx:document magic link authentication /phx:document # Auto-detect from recent plan ``` ## Iron Laws 1. **Never remove existing documentation** — Existing docs may reflect design intent that isn't obvious from code alone; update rather than replace 2. **@moduledoc on every public module** — Undocumented modules accumulate quickly and create onboarding friction for new team members 3. **ADRs capture the "why", not the "what"** — Code shows what was built; ADRs explain why this approach was chosen over alternatives 4. **Match @doc to function's public API** — Document parameters, return values, and edge cases; callers shouldn't need to read the implementation 5. **DO NOT add @doc to untested code** — documentation implies a stable contract; document only after tests confirm the function behaves as described ## What Gets Documented | Output | Description | |--------|-------------| | `@moduledoc` | For new modules missing documentation | | `@doc` | For public functions without docs | | README section | For user-facing features | | ADR | For significant architectural decisions | ## Workflow ### Step 0: Pre-check (avoid no-op runs) Run `git diff --name-only HEAD~5 | grep '\.ex$' | head -20` to check for new `.ex` files. If NO new `.ex` files were added (only modifications), skip the full audit and report: "No new modules — documentation cov...