fix: Remove unnecessary metadata and timestamps from task and workflow documentation

.claude/commands/task/create.md

@@ -103,10 +103,6 @@ Context inherited from workflow
     "last_attempt": null
   },
   
-  "meta": {
-    "created": "2025-09-05T10:30:00Z",
-    "updated": "2025-09-05T10:30:00Z"
-  }
 }
 ```
 

.claude/commands/task/replan.md

@@ -135,13 +135,11 @@ Each replan creates a new version with complete history:
   "replan_history": [
     {
       "version": "1.1",
-      "date": "2025-09-08T10:00:00Z",
       "reason": "Original plan",
       "input_source": "initial_creation"
     },
     {
       "version": "1.2", 
-      "date": "2025-09-08T14:00:00Z",
       "reason": "Add OAuth2 authentication support",
       "input_source": "direct_text",
       "changes": [
@@ -196,7 +194,7 @@ When task is replanned, the corresponding section in IMPL_PLAN.md is updated:
   - Token management (added)
   - Password reset
 
-*Last updated: 2025-09-08 14:00 via task:replan*
+*Last updated via task:replan*
 ```
 
 ### Plan Update Process