refactor(workflow): remove all .active marker file references and sync documentation

Core Changes (10 files):
- commands: cli/execute.md, memory/docs.md, workflow/review.md, workflow/brainstorm/*.md
- agents: cli-execution-agent.md
- workflows: task-core.md, workflow-architecture.md

Transformations:
- Removed all .active-* marker file operations (touch/rm/find)
- Updated session discovery to directory-based (.workflow/sessions/)
- Updated directory structure examples to show sessions/ subdirectory
- Replaced marker-based state with location-based state

Reference Documentation (57 files):
- Auto-synced via analyze_commands.py script
- Includes all core file changes
- Updated command indexes (all-commands.json, by-category.json, etc.)

Migration complete: 100% .active marker references removed
Session state now determined by directory location only

.claude/commands/workflow/brainstorm/artifacts.md

@@ -133,7 +133,7 @@ b) {role-name} ({中文名})
 ## Execution Phases
 
 ### Session Management
-- Check `.workflow/sessions/` for active sessions first
+- Check `.workflow/sessions/` for existing sessions
 - Multiple sessions → Prompt selection | Single → Use it | None → Create `WFS-[topic-slug]`
 - Parse `--count N` parameter from user input (default: 3 if not specified)
 - Store decisions in `workflow-session.json` including count parameter
@@ -597,7 +597,6 @@ ELSE:
 
 ```
 .workflow/sessions/WFS-[topic]/
-├── .active-brainstorming
 ├── workflow-session.json              # Session metadata ONLY
 └── .brainstorming/
     └── guidance-specification.md      # Full guidance content

.claude/commands/workflow/brainstorm/auto-parallel.md

@@ -392,16 +392,16 @@ CONTEXT_VARS:
 
 ## Session Management
 
-**⚡ FIRST ACTION**: Check `.workflow/sessions/` for active sessions before Phase 1
+**⚡ FIRST ACTION**: Check `.workflow/sessions/` for existing sessions before Phase 1
 
 **Multiple Sessions Support**:
-- Different Claude instances can have different active brainstorming sessions
-- If multiple active sessions found, prompt user to select
-- If single active session found, use it
-- If no active session exists, create `WFS-[topic-slug]`
+- Different Claude instances can have different brainstorming sessions
+- If multiple sessions found, prompt user to select
+- If single session found, use it
+- If no session exists, create `WFS-[topic-slug]`
 
 **Session Continuity**:
-- MUST use selected active session for all phases
+- MUST use selected session for all phases
 - Each role's context stored in session directory
 - Session isolation: Each session maintains independent state
 
@@ -447,7 +447,6 @@ CONTEXT_VARS:
 **File Structure**:
 ```
 .workflow/sessions/WFS-[topic]/
-├── .active-brainstorming
 ├── workflow-session.json              # Session metadata ONLY
 └── .brainstorming/
     ├── guidance-specification.md      # Framework (Phase 1)

.claude/commands/workflow/brainstorm/system-architect.md

@@ -186,8 +186,8 @@ IF update_mode = "incremental":
 ### ⚠️ Session Management - FIRST STEP
 Session detection and selection:
 ```bash
-# Check for active sessions
-active_sessions=$(find .workflow -name ".active-*" 2>/dev/null)
+# Check for existing sessions
+existing_sessions=$(find .workflow/sessions/ -name "WFS-*" -type d 2>/dev/null)
 if [ multiple_sessions ]; then
   prompt_user_to_select_session()
 else