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/skills/team-arch-opt/subagents/discuss-subagent.md

@@ -11,7 +11,7 @@ Complex refactoring decisions (e.g., choosing between dependency inversion vs me
 Called by designer, reviewer after their primary analysis when complexity warrants multi-perspective evaluation:
 
 ```
-Task({
+Agent({
   subagent_type: "cli-discuss-agent",
   run_in_background: false,
   description: "Discuss <round-id>: <topic> for architecture optimization",

.claude/skills/team-arch-opt/subagents/explore-subagent.md

@@ -11,7 +11,7 @@ Codebase exploration is a read-only operation shared between analyzer (mapping s
 Called by analyzer, refactorer after needing codebase context for architecture analysis or implementation:
 
 ```
-Task({
+Agent({
   subagent_type: "cli-explore-agent",
   run_in_background: false,
   description: "Explore codebase for architecture-critical structures in <target-scope>",