refactor(workflow): complete migration from .workflow/sessions/ to .workflow/active/ directory structure

Update all command files to use the new standardized directory structure:
- Active sessions: .workflow/active/WFS-{session}/
- Archived sessions: .workflow/archives/WFS-{session}/

Changes:
- Updated workflow-architecture.md with new directory structure (active/ not sessions/)
- Fixed 31 path references across 12 command files
- Verified compliance across all 73 command files using parallel agent checks
- Confirmed directory naming: active/ (adjective, no plural) + archives/ (noun plural)

Files modified:
- .claude/workflows/workflow-architecture.md (directory structure definition)
- .claude/commands/cli/*.md (8 files: analyze, chat, codex-execute, discuss-plan, execute, mode/*)
- .claude/commands/memory/docs.md (4 path fixes)
- .claude/commands/task/*.md (execute, replan)

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

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

.claude/commands/cli/analyze.md

@@ -75,7 +75,7 @@ Task(
     4. Execution & Output:
        - Execute CLI tool with assembled context
        - Generate comprehensive analysis report
-       - Save to .workflow/WFS-[id]/.chat/analyze-[timestamp].md (or .scratchpad/)
+       - Save to .workflow/active/WFS-[id]/.chat/analyze-[timestamp].md (or .scratchpad/)
   `
 )
 ```
@@ -84,4 +84,4 @@ Task(
 
 - **Read-only**: Analyzes code, does NOT modify files
 - **Auto-pattern**: Detects file patterns from keywords (auth→auth files, component→components, API→api/routes, test→test files)
-- **Output**: `.workflow/WFS-[id]/.chat/analyze-[timestamp].md` (or `.scratchpad/` if no session)
+- **Output**: `.workflow/active/WFS-[id]/.chat/analyze-[timestamp].md` (or `.scratchpad/` if no session)