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/task/replan.md

@@ -274,7 +274,7 @@ Backup saved to .task/backup/IMPL-2-v1.0.json
 
 ### Batch Mode - From Verification Report
 ```bash
-/task:replan --batch .workflow/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md
+/task:replan --batch .workflow/active/WFS-{session}/.process/ACTION_PLAN_VERIFICATION.md
 
 Parsing verification report...
 Found 4 tasks requiring replanning: