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/workflow/ui-design/reference-page-generator.md

@@ -2,7 +2,7 @@
 name: workflow:ui-design:reference-page-generator
 description: Generate multi-component reference pages and documentation from design run extraction
 argument-hint: "[--design-run <path>] [--package-name <name>] [--output-dir <path>]"
-allowed-tools: Read,Write,Bash,Task,TodoWrite
+allowed-tools: Read,Write,Bash,Agent,TodoWrite
 auto-continue: true
 ---
 
@@ -198,7 +198,7 @@ echo "[Phase 1] Component data preparation complete"
 **Agent Task**:
 
 ```javascript
-Task(ui-design-agent): `
+Agent(ui-design-agent): `
   [PREVIEW_SHOWCASE_GENERATION]
   Generate interactive multi-component showcase panel for reference package
 
@@ -210,7 +210,7 @@ Task(ui-design-agent): `
   2. ${package_dir}/design-tokens.json (design tokens - REQUIRED)
   3. ${package_dir}/animation-tokens.json (optional, if exists)
 
-  ## Generation Task
+  ## Generation Agent
 
   Create interactive showcase with these sections: