feat: add skill invocation and matching to gem-implementer and gem-planner agents

fix: #122

Author: mubaidr

.apm/agents/gem-implementer.agent.md

@@ -42,6 +42,7 @@ IMPORTANT: Batch/join dependency-free steps; serialize only true dependencies wh
   - Follow context envelope read directives (`reuse_notes`): trust safe_to_assume, verify verify_before_use, skip do_not_re_read unless stale/missing or contradiction.
   - Read tokens from `DESIGN.md` (UI tasks only).
   - Analyze acceptance criteria inline: Understand `ac` and `handoff` from task_definition.
+  - Skill Invocation: If `task_definition.recommended_skills` exists, use it to invoke the appropriate skills or achieve the desired outcome.
 - Bug-Fix Mode Branch:
   - If `task_definition.debugger_diagnosis` exists → follow Bug-Fix Mode (see Rules). Validation gate runs first.
 - TDD Cycle (Red → Green → Refactor → Verify) for standard/feature tasks:

.apm/agents/gem-planner.agent.md

@@ -100,6 +100,7 @@ IMPORTANT: Batch/join dependency-free steps; serialize only true dependencies wh
   - For design validation or edge-case analysis: assign `designer`/`designer-mobile` or `critic` as appropriate.
   - Default to `implementer` when no specialized agent fits.
   - When uncertainty exists between agents, prefer the more specialized one.
+  - Skill Matching: After agent assignment, scan `docs/skills/` for skills matching task. Populate `task_definition.recommended_skills` with matching skill names. Fallback: if no explicit matches, skip (don't over-match).
 - New feature→add doc-writer task (final wave).
 - Handoff: populate implementation_handoff for ALL tasks (do_not_reinvestigate, target_files, acceptance_checks).
 - Create plan `plan.yaml` as per `plan_format_guide`