fix: smart enhancement dispatcher — Gemini/API mode + root/Docker detection

Fixes issues #289 and #286 (agent switching and Docker/root failures).

enhance_command.py (new smart dispatcher):
- Routes skill-seekers enhance to API mode (Gemini/OpenAI/Claude API)
  when an API key is available, or LOCAL mode (Claude Code CLI) otherwise
- Decision priority: --target flag > config default_agent > auto-detect
  from env vars (ANTHROPIC_API_KEY → claude, GOOGLE_API_KEY → gemini,
  OPENAI_API_KEY → openai) > LOCAL fallback
- Blocks LOCAL mode when running as root (Docker/VPS) with clear error
  message + API mode instructions
- Supports --dry-run, --target, --api-key as first-class flags

arguments/enhance.py:
- Added --target, --api-key, --dry-run, --interactive-enhancement to
  ENHANCE_ARGUMENTS (shared by unified CLI parser and standalone entry point)

enhance_skill_local.py:
- Error output no longer truncated at 200 chars (shows up to 20 lines)
- Detects root/permission errors in stderr and prints actionable hint

config_manager.py:
- Added default_agent field to DEFAULT_CONFIG ai_enhancement section
- Added get_default_agent() and set_default_agent() methods

main.py:
- enhance command routed to enhance_command (was enhance_skill_local)
- _handle_analyze_command uses smart dispatcher for post-analysis enhancement

pyproject.toml:
- skill-seekers-enhance entry point updated to enhance_command:main

Tests: 1977 passed, 0 failed (28 new tests in test_enhance_command.py)

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

src/skill_seekers/cli/main.py

@@ -14,7 +14,7 @@ Commands:
     pdf                  Extract from PDF file
     unified              Multi-source scraping (docs + GitHub + PDF)
     analyze              Analyze local codebase and extract code knowledge
-    enhance              AI-powered enhancement (local, no API key)
+    enhance              AI-powered enhancement (auto: API or LOCAL mode)
     enhance-status       Check enhancement status (for background/daemon modes)
     package              Package skill into .zip file
     upload               Upload skill to Claude
@@ -48,7 +48,7 @@ COMMAND_MODULES = {
     "github": "skill_seekers.cli.github_scraper",
     "pdf": "skill_seekers.cli.pdf_scraper",
     "unified": "skill_seekers.cli.unified_scraper",
-    "enhance": "skill_seekers.cli.enhance_skill_local",
+    "enhance": "skill_seekers.cli.enhance_command",
     "enhance-status": "skill_seekers.cli.enhance_status",
     "package": "skill_seekers.cli.package_skill",
     "upload": "skill_seekers.cli.upload_skill",
@@ -320,10 +320,39 @@ def _handle_analyze_command(args: argparse.Namespace) -> int:
                 print("=" * 60 + "\n")
 
                 try:
-                    from skill_seekers.cli.enhance_skill_local import LocalSkillEnhancer
+                    from skill_seekers.cli.enhance_command import (
+                        _is_root,
+                        _pick_mode,
+                        _run_api_mode,
+                        _run_local_mode,
+                    )
+                    import argparse as _ap
 
-                    enhancer = LocalSkillEnhancer(str(skill_dir), force=True)
-                    success = enhancer.run(headless=True, timeout=600)
+                    _fake_args = _ap.Namespace(
+                        skill_directory=str(skill_dir),
+                        target=None,
+                        api_key=None,
+                        dry_run=False,
+                        agent=None,
+                        agent_cmd=None,
+                        interactive_enhancement=False,
+                        background=False,
+                        daemon=False,
+                        no_force=False,
+                        timeout=600,
+                    )
+                    _mode, _target = _pick_mode(_fake_args)
+
+                    if _mode == "api":
+                        print(f"\n🤖 Enhancement mode: API ({_target})")
+                        success = _run_api_mode(_fake_args, _target) == 0
+                    elif _is_root():
+                        print("\n⚠️  Skipping SKILL.md enhancement: running as root")
+                        print("   Set ANTHROPIC_API_KEY / GOOGLE_API_KEY to enable API mode")
+                        success = False
+                    else:
+                        print("\n🤖 Enhancement mode: LOCAL (Claude Code CLI)")
+                        success = _run_local_mode(_fake_args) == 0
 
                     if success:
                         print("\n✅ SKILL.md enhancement complete!")