fix(workflow): complete path migration and enhance session:complete

Comprehensive update to eliminate all old path references and implement transactional archival in session:complete.

## Part 1: Complete Path Migration (43 files)

### Files Updated
- action-plan-verify.md
- session/list.md, session/resume.md
- tdd-verify.md, tdd-plan.md, test-*.md
- All brainstorm/*.md files (13 files)
- All tools/*.md files (10 files)
- All ui-design/*.md files (10 files)
- lite-plan.md, lite-execute.md, plan.md

### Path Changes
- `.workflow/.active-*` → `find .workflow/sessions/ -name "WFS-*" -type d`
- `.workflow/WFS-{session}` → `.workflow/sessions/WFS-{session}`
- `.workflow/.archives/` → `.workflow/archives/`
- Removed all marker file operations (touch/rm .active-*)

### Verification
- ✅ 0 references to .active-* markers remain
- ✅ 0 references to direct .workflow/WFS-* paths
- ✅ 0 references to .workflow/.archives/ (dot prefix)

## Part 2: Transactional Archival Enhancement

### session/complete.md - Complete Rewrite

**New Four-Phase Architecture**:

1. **Phase 1: Pre-Archival Preparation**
   - Find active session in .workflow/sessions/
   - Check for existing .archiving marker (resume detection)
   - Create .archiving marker to prevent concurrent operations

2. **Phase 2: Agent Analysis (In-Place)**
   - Agent processes session WHILE STILL in sessions/ directory
   - Pure analysis - no file moves or manifest updates
   - Returns complete metadata package for atomic commit
   - Failure here → session remains active, safe to retry

3. **Phase 3: Atomic Commit**
   - Only executes if Phase 2 succeeds
   - Move session to archives/
   - Update manifest.json
   - Remove .archiving marker
   - All-or-nothing guarantee

4. **Phase 4: Project Registry Update**
   - Extract feature metadata and update project.json

**Key Improvements**:
- **Agent-first, move-second**: Prevents inconsistent states
- **Transactional guarantees**: All-or-nothing file operations
- **Resume capability**: .archiving marker enables safe retry
- **Error recovery**: Comprehensive failure handling documented

**Old Design Flaw (Fixed)**:
- Old: Move first → Agent processes → If agent fails, session moved but metadata incomplete
- New: Agent processes → If success, atomic commit → Guaranteed consistency

## Benefits

1. **Consistency**: All commands use identical path patterns
2. **Robustness**: Transactional archival prevents data loss
3. **Maintainability**: Single source of truth for directory structure
4. **Recoverability**: Failed operations can be safely retried
5. **Alignment**: Closer to OpenSpec's clean three-layer model

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/commands/workflow/action-plan-verify.md

@@ -32,7 +32,7 @@ Identify inconsistencies, duplications, ambiguities, and underspecified items be
 IF --session parameter provided:
     session_id = provided session
 ELSE:
-    CHECK: .workflow/.active-* marker files
+    CHECK: find .workflow/sessions/ -name "WFS-*" -type d
     IF active_session EXISTS:
         session_id = get_active_session()
     ELSE:
@@ -40,7 +40,7 @@ ELSE:
         EXIT
 
 # Derive absolute paths
-session_dir = .workflow/WFS-{session}
+session_dir = .workflow/sessions/WFS-{session}
 brainstorm_dir = session_dir/.brainstorming
 task_dir = session_dir/.task
 
@@ -333,7 +333,7 @@ Output a Markdown report (no file writes) with the following structure:
 
 #### TodoWrite-Based Remediation Workflow
 
-**Report Location**: `.workflow/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md`
+**Report Location**: `.workflow/sessions/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md`
 
 **Recommended Workflow**:
 1. **Create TodoWrite Task List**: Extract all findings from report
@@ -361,7 +361,7 @@ Priority Order:
 
 **Save Analysis Report**:
 ```bash
-report_path = ".workflow/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md"
+report_path = ".workflow/sessions/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md"
 Write(report_path, full_report_content)
 ```
 
@@ -404,12 +404,12 @@ TodoWrite([
 **File Modification Workflow**:
 ```bash
 # For task JSON modifications:
-1. Read(.workflow/WFS-{session}/.task/IMPL-X.Y.json)
+1. Read(.workflow/sessions/WFS-{session}/.task/IMPL-X.Y.json)
 2. Edit() to apply fixes
 3. Mark todo as completed
 
 # For IMPL_PLAN modifications:
-1. Read(.workflow/WFS-{session}/IMPL_PLAN.md)
+1. Read(.workflow/sessions/WFS-{session}/IMPL_PLAN.md)
 2. Edit() to apply strategic changes
 3. Mark todo as completed
 ```