refactor: replace Task tool with Agent tool and fix schema compliance

## Task -> Agent Replacement
- Replace all Task({}) calls with Agent({}) across .claude/ directory
- Update allowed-tools declarations from Task to Agent
- Update documentation references from "Task tool" to "Agent tool"

## Schema Compliance Fixes

### Agent Schema
- Add missing required `description` parameter in 6 files
- Add missing `run_in_background: false` for subagent calls
- Add missing `subagent_type` parameter

### AskUserQuestion Schema
- Fix issue-manage/SKILL.md: reduce options from 5 to 4 (max allowed)

### SendMessage Schema
- Fix team-worker.md: use correct params (type, content, summary)
- Remove invalid `team_name` parameter

### TaskCreate/TaskUpdate Schema
- Remove invalid `blockedBy`, `owner`, `status` from TaskCreate calls
- Use separate TaskUpdate calls for dependencies and ownership
- Fix TaskUpdate syntax to use object parameter

### TeamDelete Schema
- Remove parameters from TeamDelete() calls (should be no params)

### TaskOutput Schema
- Fix Python-style syntax to JavaScript object syntax

## Files Changed
- 146 files updated across commands/, skills/, skills_lib/, agents/

.claude/commands/issue/plan.md

@@ -2,7 +2,7 @@
 name: plan
 description: Batch plan issue resolution using issue-plan-agent (explore + plan closed-loop)
 argument-hint: "[-y|--yes] --all-pending <issue-id>[,<issue-id>,...] [--batch-size 3]"
-allowed-tools: TodoWrite(*), Task(*), Skill(*), AskUserQuestion(*), Bash(*), Read(*), Write(*)
+allowed-tools: TodoWrite(*), Agent(*), Skill(*), AskUserQuestion(*), Bash(*), Read(*), Write(*)
 ---
 
 ## Auto Mode
@@ -222,7 +222,7 @@ for (let i = 0; i < agentTasks.length; i += MAX_PARALLEL) {
 
   // Collect results from this chunk
   for (const { taskId, batchIndex } of taskIds) {
-    const result = TaskOutput(task_id=taskId, block=true);
+    const result = TaskOutput({ task_id: taskId, block: true });
 
     // Extract JSON from potential markdown code blocks (agent may wrap in ```json...```)
     const jsonText = extractJsonFromMarkdown(result);