feat: Unified create command + consolidated enhancement flags

This commit includes two major improvements:

## 1. Unified Create Command (v3.0.0 feature)
- Auto-detects source type (web, GitHub, local, PDF, config)
- Three-tier argument organization (universal, source-specific, advanced)
- Routes to existing scrapers (100% backward compatible)
- Progressive disclosure: 15 universal flags in default help

**New files:**
- src/skill_seekers/cli/source_detector.py - Auto-detection logic
- src/skill_seekers/cli/arguments/create.py - Argument definitions
- src/skill_seekers/cli/create_command.py - Main orchestrator
- src/skill_seekers/cli/parsers/create_parser.py - Parser integration

**Tests:**
- tests/test_source_detector.py (35 tests)
- tests/test_create_arguments.py (30 tests)
- tests/test_create_integration_basic.py (10 tests)

## 2. Enhanced Flag Consolidation (Phase 1)
- Consolidated 3 flags (--enhance, --enhance-local, --enhance-level) → 1 flag
- --enhance-level 0-3 with auto-detection of API vs LOCAL mode
- Default: --enhance-level 2 (balanced enhancement)

**Modified files:**
- arguments/{common,create,scrape,github,analyze}.py - Added enhance_level
- {doc_scraper,github_scraper,config_extractor,main}.py - Updated logic
- create_command.py - Uses consolidated flag

**Auto-detection:**
- If ANTHROPIC_API_KEY set → API mode
- Else → LOCAL mode (Claude Code)

## 3. PresetManager Bug Fix
- Fixed module naming conflict (presets.py vs presets/ directory)
- Moved presets.py → presets/manager.py
- Updated __init__.py exports

**Test Results:**
- All 160+ tests passing
- Zero regressions
- 100% backward compatible

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/skill_seekers/cli/parsers/scrape_parser.py

@@ -1,6 +1,11 @@
-"""Scrape subcommand parser."""
+"""Scrape subcommand parser.
+
+Uses shared argument definitions from arguments.scrape to ensure
+consistency with the standalone doc_scraper module.
+"""
 
 from .base import SubcommandParser
+from skill_seekers.cli.arguments.scrape import add_scrape_arguments
 
 
 class ScrapeParser(SubcommandParser):
@@ -19,24 +24,12 @@ class ScrapeParser(SubcommandParser):
         return "Scrape documentation website and generate skill"
 
     def add_arguments(self, parser):
-        """Add scrape-specific arguments."""
-        parser.add_argument("url", nargs="?", help="Documentation URL (positional argument)")
-        parser.add_argument("--config", help="Config JSON file")
-        parser.add_argument("--name", help="Skill name")
-        parser.add_argument("--description", help="Skill description")
-        parser.add_argument(
-            "--max-pages",
-            type=int,
-            dest="max_pages",
-            help="Maximum pages to scrape (override config)",
-        )
-        parser.add_argument(
-            "--skip-scrape", action="store_true", help="Skip scraping, use cached data"
-        )
-        parser.add_argument("--enhance", action="store_true", help="AI enhancement (API)")
-        parser.add_argument("--enhance-local", action="store_true", help="AI enhancement (local)")
-        parser.add_argument("--dry-run", action="store_true", help="Dry run mode")
-        parser.add_argument(
-            "--async", dest="async_mode", action="store_true", help="Use async scraping"
-        )
-        parser.add_argument("--workers", type=int, help="Number of async workers")
+        """Add scrape-specific arguments.
+        
+        Uses shared argument definitions to ensure consistency
+        with doc_scraper.py (standalone scraper).
+        """
+        # Add all scrape arguments from shared definitions
+        # This ensures the unified CLI has exactly the same arguments
+        # as the standalone scraper - they CANNOT drift out of sync
+        add_scrape_arguments(parser)