feat: standardize request_user_input schema across all codex skills and add config reminder

- Update all 68 .codex/skills files to use correct request_user_input schema
  (header, id, question, options with label/description)
- Remove deprecated multiSelect, type, value, prompt fields
- Add mandatory confirmation gates to planning-only skills
- Add Codex config.toml reminder to ccw install CLI
- Add Codex configuration section to README.md and README_CN.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.codex/skills/team-tech-debt/agents/plan-approver.md

@@ -36,7 +36,7 @@ Interactive agent for reviewing the tech debt remediation plan at the plan appro
 | Tool | Type | Purpose |
 |------|------|---------|
 | `Read` | built-in | Load plan artifacts and context |
-| `AskUserQuestion` | built-in | Get user approval decision |
+| `request_user_input` | built-in | Get user approval decision |
 | `Write` | built-in | Store approval result |
 
 ### Tool Usage Patterns
@@ -91,13 +91,13 @@ Read("<session>/assessment/priority-matrix.json")
 2. Present decision:
 
 ```javascript
-AskUserQuestion({
+request_user_input({
   questions: [{
     question: "Remediation plan generated. Review and decide:",
-    header: "Plan Approval Gate",
-    multiSelect: false,
+    header: "Plan Approval",
+    id: "plan_approval",
     options: [
-      { label: "Approve", description: "Proceed with fix execution in worktree" },
+      { label: "Approve (Recommended)", description: "Proceed with fix execution in worktree" },
       { label: "Revise", description: "Re-run planner with specific feedback" },
       { label: "Abort", description: "Stop pipeline, keep scan/assessment results" }
     ]