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/arguments/common.py

@@ -0,0 +1,111 @@
+"""Common CLI arguments shared across multiple commands.
+
+These arguments are used by most commands (scrape, github, pdf, analyze, etc.)
+and provide consistent behavior for configuration, output control, and help.
+"""
+
+import argparse
+from typing import Dict, Any
+
+
+# Common argument definitions as data structure
+# These are arguments that appear in MULTIPLE commands
+COMMON_ARGUMENTS: Dict[str, Dict[str, Any]] = {
+    "config": {
+        "flags": ("--config", "-c"),
+        "kwargs": {
+            "type": str,
+            "help": "Load configuration from JSON file (e.g., configs/react.json)",
+            "metavar": "FILE",
+        },
+    },
+    "name": {
+        "flags": ("--name",),
+        "kwargs": {
+            "type": str,
+            "help": "Skill name (used for output directory and filenames)",
+            "metavar": "NAME",
+        },
+    },
+    "description": {
+        "flags": ("--description", "-d"),
+        "kwargs": {
+            "type": str,
+            "help": "Skill description (used in SKILL.md)",
+            "metavar": "TEXT",
+        },
+    },
+    "output": {
+        "flags": ("--output", "-o"),
+        "kwargs": {
+            "type": str,
+            "help": "Output directory (default: auto-generated from name)",
+            "metavar": "DIR",
+        },
+    },
+    "enhance_level": {
+        "flags": ("--enhance-level",),
+        "kwargs": {
+            "type": int,
+            "choices": [0, 1, 2, 3],
+            "default": 2,
+            "help": (
+                "AI enhancement level (auto-detects API vs LOCAL mode): "
+                "0=disabled, 1=SKILL.md only, 2=+architecture/config (default), 3=full enhancement. "
+                "Mode selection: uses API if ANTHROPIC_API_KEY is set, otherwise LOCAL (Claude Code)"
+            ),
+            "metavar": "LEVEL",
+        },
+    },
+    "api_key": {
+        "flags": ("--api-key",),
+        "kwargs": {
+            "type": str,
+            "help": "Anthropic API key for --enhance (or set ANTHROPIC_API_KEY env var)",
+            "metavar": "KEY",
+        },
+    },
+}
+
+
+def add_common_arguments(parser: argparse.ArgumentParser) -> None:
+    """Add common arguments to a parser.
+    
+    These arguments are shared across most commands for consistent UX.
+    
+    Args:
+        parser: The ArgumentParser to add arguments to
+        
+    Example:
+        >>> parser = argparse.ArgumentParser()
+        >>> add_common_arguments(parser)
+        >>> # Now parser has --config, --name, --description, etc.
+    """
+    for arg_name, arg_def in COMMON_ARGUMENTS.items():
+        flags = arg_def["flags"]
+        kwargs = arg_def["kwargs"]
+        parser.add_argument(*flags, **kwargs)
+
+
+def get_common_argument_names() -> set:
+    """Get the set of common argument destination names.
+    
+    Returns:
+        Set of argument dest names (e.g., {'config', 'name', 'description', ...})
+    """
+    return set(COMMON_ARGUMENTS.keys())
+
+
+def get_argument_help(arg_name: str) -> str:
+    """Get the help text for a common argument.
+    
+    Args:
+        arg_name: Name of the argument (e.g., 'config')
+        
+    Returns:
+        Help text string
+        
+    Raises:
+        KeyError: If argument doesn't exist
+    """
+    return COMMON_ARGUMENTS[arg_name]["kwargs"]["help"]