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/explore-auto.md

@@ -2,7 +2,7 @@
 name: explore-auto
 description: Interactive exploratory UI design workflow with style-centric batch generation, creates design variants from prompts/images with parallel execution and user selection
 argument-hint: "[--input "<value>"] [--targets "<list>"] [--target-type "page|component"] [--session <id>] [--style-variants <count>] [--layout-variants <count>]"
-allowed-tools: Skill(*), TodoWrite(*), Read(*), Bash(*), Glob(*), Write(*), Task(conceptual-planning-agent)
+allowed-tools: Skill(*), TodoWrite(*), Read(*), Bash(*), Glob(*), Write(*), Agent(conceptual-planning-agent)
 ---
 
 # UI Design Auto Workflow Command