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/skill-tuning/specs/tuning-strategies.md

@@ -140,8 +140,10 @@ function updateHistory(state, newItem) {
 
 ```javascript
 // Add summarization before passing to next phase
-const summary = await Task({
+const summary = await Agent({
   subagent_type: 'universal-executor',
+  description: 'Summarize content for context compression',
+  run_in_background: false,
   prompt: `Summarize in <100 words: ${fullContent}\nReturn JSON: { summary, key_points[] }`
 });
 nextPhasePrompt = `Previous summary: ${summary.summary}`;
@@ -268,12 +270,17 @@ function validateAgentResult(result, requiredFields) {
 ### flatten_nesting
 
 ```javascript
-// Before: Agent A's prompt tells it to call Task({subagent_type: 'B'})
+// Before: Agent A's prompt tells it to call Agent({subagent_type: 'B'})
 // After: Agent A returns signal, orchestrator handles
 // Agent A: return { needs_agent_b: true, context: {...} }
 // Orchestrator:
 if (parsedA.needs_agent_b) {
-  resultB = await Task({ subagent_type: 'B', prompt: `Context: ${parsedA.context}` });
+  resultB = await Agent({
+    subagent_type: 'B',
+    description: 'Handle delegated task from Agent A',
+    run_in_background: false,
+    prompt: `Context: ${parsedA.context}`
+  });
 }
 ```