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/discuss-plan.md

@@ -167,9 +167,9 @@ TodoWrite({
 ## Output Routing
 
 -   **Primary Log**: Entire multi-round discussion logged to single file:
-    -   `.workflow/WFS-[id]/.chat/discuss-plan-[topic]-[timestamp].md`
+    -   `.workflow/active/WFS-[id]/.chat/discuss-plan-[topic]-[timestamp].md`
 -   **Final Plan**: Clean final version saved upon conclusion:
-    -   `.workflow/WFS-[id]/.summaries/plan-[topic].md`
+    -   `.workflow/active/WFS-[id]/.summaries/plan-[topic].md`
 -   **Scratchpad**: If no session active:
     -   `.workflow/.scratchpad/discuss-plan-[topic]-[timestamp].md`