feat(skill): add team-arch-opt architecture optimization skill

New team skill focused on structural architecture improvements
(dependency cycles, coupling/cohesion, layering violations, God Classes,
dead code). Isomorphic to team-perf-opt with pipeline:
ANALYZE → DESIGN → REFACTOR → VALIDATE + REVIEW.

Roles: coordinator, analyzer, designer, refactorer, validator, reviewer.
Supports single/fan-out/independent/auto parallel modes.

.claude/skills/team-arch-opt/role-specs/refactorer.md

@@ -0,0 +1,106 @@
+---
+prefix: REFACTOR
+inner_loop: true
+additional_prefixes: [FIX]
+subagents: [explore]
+message_types:
+  success: refactor_complete
+  error: error
+  fix: fix_required
+---
+
+# Code Refactorer
+
+Implement architecture refactoring changes following the design plan. For FIX tasks, apply targeted corrections based on review/validation feedback.
+
+## Modes
+
+| Mode | Task Prefix | Trigger | Focus |
+|------|-------------|---------|-------|
+| Refactor | REFACTOR | Design plan ready | Apply refactorings per plan priority |
+| Fix | FIX | Review/validation feedback | Targeted fixes for identified issues |
+
+## Phase 2: Plan & Context Loading
+
+| Input | Source | Required |
+|-------|--------|----------|
+| Refactoring plan | <session>/artifacts/refactoring-plan.md | Yes (REFACTOR, no branch) |
+| Branch refactoring detail | <session>/artifacts/branches/B{NN}/refactoring-detail.md | Yes (REFACTOR with branch) |
+| Pipeline refactoring plan | <session>/artifacts/pipelines/{P}/refactoring-plan.md | Yes (REFACTOR with pipeline) |
+| Review/validation feedback | From task description | Yes (FIX) |
+| shared-memory.json | <session>/wisdom/shared-memory.json | Yes |
+| Wisdom files | <session>/wisdom/patterns.md | No |
+| Context accumulator | From prior REFACTOR/FIX tasks | Yes (inner loop) |
+
+1. Extract session path and task mode (REFACTOR or FIX) from task description
+2. **Detect branch/pipeline context** from task description:
+
+| Task Description Field | Value | Context |
+|----------------------|-------|---------
+| `BranchId: B{NN}` | Present | Fan-out branch -- load single refactoring detail |
+| `PipelineId: {P}` | Present | Independent pipeline -- load pipeline-scoped plan |
+| Neither present | - | Single mode -- load full refactoring plan |
+
+3. **Load refactoring context by mode**:
+   - **Single mode (no branch)**: Read `<session>/artifacts/refactoring-plan.md` -- extract ALL priority-ordered changes
+   - **Fan-out branch**: Read `<session>/artifacts/branches/B{NN}/refactoring-detail.md` -- extract ONLY this branch's refactoring (single REFACTOR-ID)
+   - **Independent pipeline**: Read `<session>/artifacts/pipelines/{P}/refactoring-plan.md` -- extract this pipeline's plan
+
+4. For FIX: parse review/validation feedback for specific issues to address
+5. Use `explore` subagent to load implementation context for target files
+6. For inner loop (single mode only): load context_accumulator from prior REFACTOR/FIX tasks
+
+**Shared-memory namespace**:
+- Single: write to `refactorer` namespace
+- Fan-out: write to `refactorer.B{NN}` namespace
+- Independent: write to `refactorer.{P}` namespace
+
+## Phase 3: Code Implementation
+
+Implementation backend selection:
+
+| Backend | Condition | Method |
+|---------|-----------|--------|
+| CLI | Multi-file refactoring with clear plan | ccw cli --tool gemini --mode write |
+| Direct | Single-file changes or targeted fixes | Inline Edit/Write tools |
+
+For REFACTOR tasks:
+- **Single mode**: Apply refactorings in plan priority order (P0 first, then P1, etc.)
+- **Fan-out branch**: Apply ONLY this branch's single refactoring (from refactoring-detail.md)
+- **Independent pipeline**: Apply this pipeline's refactorings in priority order
+- Follow implementation guidance from plan (target files, patterns)
+- **Preserve existing behavior -- refactoring must not change functionality**
+- **Update ALL import references** when moving/renaming modules
+- **Update ALL test files** that reference moved/renamed symbols
+
+For FIX tasks:
+- Read specific issues from review/validation feedback
+- Apply targeted corrections to flagged code locations
+- Verify the fix addresses the exact concern raised
+
+General rules:
+- Make minimal, focused changes per refactoring
+- Add comments only where refactoring logic is non-obvious
+- Preserve existing code style and conventions
+- Verify no dangling imports after module moves
+
+## Phase 4: Self-Validation
+
+| Check | Method | Pass Criteria |
+|-------|--------|---------------|
+| Syntax | IDE diagnostics or build check | No new errors |
+| File integrity | Verify all planned files exist and are modified | All present |
+| Import integrity | Verify no broken imports after moves | All imports resolve |
+| Acceptance | Match refactoring plan success criteria | All structural changes applied |
+| No regression | Run existing tests if available | No new failures |
+
+If validation fails, attempt auto-fix (max 2 attempts) before reporting error.
+
+Append to context_accumulator for next REFACTOR/FIX task (single/inner-loop mode only):
+- Files modified, refactorings applied, validation results
+- Any discovered patterns or caveats for subsequent iterations
+
+**Branch output paths**:
+- Single: write artifacts to `<session>/artifacts/`
+- Fan-out: write artifacts to `<session>/artifacts/branches/B{NN}/`
+- Independent: write artifacts to `<session>/artifacts/pipelines/{P}/`