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