feat(skills): add per-task skill spec auto-detection and injection

Replace external inject-spec.py hook with built-in zero-config skill
detection in codeagent-wrapper. The system auto-detects project type
from fingerprint files (go.mod, package.json, etc.), maps to installed
skills, and injects SKILL.md content directly into sub-agent prompts.

Key changes:
- Add DetectProjectSkills/ResolveSkillContent in executor/prompt.go
- Add Skills field to TaskSpec with parallel config parsing
- Add --skills CLI flag for explicit override
- Update /do SKILL.md Phase 4 with per-task skill examples
- Remove on-stop.py global hook (not needed)
- Replace inject-spec.py with no-op (detection now internal)
- Add 20 unit tests covering detection, resolution, budget, security

Security: path traversal protection via validSkillName regex,
16K char budget with tag overhead accounting, CRLF normalization.

Generated with SWE-Agent.ai

Co-Authored-By: SWE-Agent.ai <noreply@swe-agent.ai>

hooks/log-prompt.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""
+Log Prompt Hook - Record user prompts to session-specific log files.
+Used for review on Stop.
+Uses session-isolated logs to handle concurrency.
+"""
+
+import json
+import os
+import sys
+from datetime import datetime
+from pathlib import Path
+
+
+def get_session_id() -> str:
+    """Get unique session identifier."""
+    return os.environ.get("CLAUDE_CODE_SSE_PORT", "default")
+
+
+def write_log(prompt: str) -> None:
+    """Write prompt to session log file."""
+    log_dir = Path(".claude/state")
+    session_id = get_session_id()
+    log_file = log_dir / f"session-{session_id}.log"
+
+    log_dir.mkdir(parents=True, exist_ok=True)
+
+    timestamp = datetime.now().isoformat()
+    entry = f"[{timestamp}] {prompt[:500]}\n"
+
+    with open(log_file, "a", encoding="utf-8") as f:
+        f.write(entry)
+
+
+def main():
+    input_data = ""
+    if not sys.stdin.isatty():
+        try:
+            input_data = sys.stdin.read()
+        except Exception:
+            pass
+
+    prompt = ""
+    try:
+        data = json.loads(input_data)
+        prompt = data.get("prompt", "")
+    except json.JSONDecodeError:
+        prompt = input_data.strip()
+
+    if prompt:
+        write_log(prompt)
+
+
+if __name__ == "__main__":
+    main()