fix: unify metadata location and improve installer UX

## Changes

### Unified Metadata Location
- All components now use `~/.claude/.superclaude-metadata.json`
- Previously split between root and superclaude subdirectory
- Automatic migration from old location on first load
- Eliminates confusion from duplicate metadata files

### Improved Installation Messages
- Changed WARNING to INFO for existing installations
- Message now clearly states "will be updated" instead of implying problem
- Reduces user confusion during reinstalls/updates

### Updated Makefile
- `make install`: Development mode (uv, local source, editable)
- `make install-release`: Production mode (pipx, from PyPI)
- `make dev`: Alias for install
- Improved help output with categorized commands

## Technical Details

**Metadata Unification** (setup/services/settings.py):
- SettingsService now always uses `~/.claude/.superclaude-metadata.json`
- Added `_migrate_old_metadata()` for automatic migration
- Deep merge strategy preserves existing data
- Old file backed up as `.superclaude-metadata.json.migrated`

**User File Protection**:
- Verified: User-created files preserved during updates
- Only SuperClaude-managed files (tracked in metadata) are updated
- Obsolete framework files automatically removed

## Migration Path

Existing installations automatically migrate on next `make install`:
1. Old metadata detected at `~/.claude/superclaude/.superclaude-metadata.json`
2. Merged into `~/.claude/.superclaude-metadata.json`
3. Old file backed up
4. No user action required

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Makefile

@@ -1,17 +1,21 @@
-.PHONY: install dev test clean lint format uninstall update translate help
+.PHONY: install install-release dev test clean lint format uninstall update translate help
 
-# Full installation (dependencies + SuperClaude components)
+# Development installation (local source, editable)
 install:
-	@echo "Installing SuperClaude Framework..."
+	@echo "Installing SuperClaude Framework (development mode)..."
 	uv pip install -e ".[dev]"
 	uv run superclaude install
 
-# Install dependencies and SuperClaude (for development)
-dev:
-	@echo "Installing development dependencies..."
-	uv pip install -e ".[dev]"
-	@echo "Installing SuperClaude components..."
-	uv run superclaude install
+# Production installation (from PyPI, recommended for users)
+install-release:
+	@echo "Installing SuperClaude Framework (production mode)..."
+	@echo "Using pipx for isolated environment..."
+	pipx install SuperClaude
+	pipx upgrade SuperClaude
+	superclaude install
+
+# Alias for development installation
+dev: install
 
 # Run tests
 test:
@@ -69,13 +73,21 @@ translate:
 help:
 	@echo "SuperClaude Framework - Available commands:"
 	@echo ""
-	@echo "  make install    - Full installation (dependencies + components)"
-	@echo "  make dev        - Install development dependencies only"
-	@echo "  make test       - Run tests"
-	@echo "  make lint       - Run linter"
-	@echo "  make format     - Format code"
-	@echo "  make clean      - Clean build artifacts"
-	@echo "  make uninstall  - Uninstall SuperClaude components"
-	@echo "  make update     - Update SuperClaude components"
-	@echo "  make translate  - Translate README to Chinese and Japanese (requires Ollama)"
-	@echo "  make help       - Show this help message"
+	@echo "Installation:"
+	@echo "  make install         - Development installation (local source, editable with uv)"
+	@echo "  make install-release - Production installation (from PyPI with pipx)"
+	@echo "  make dev             - Alias for 'make install'"
+	@echo ""
+	@echo "Development:"
+	@echo "  make test            - Run tests"
+	@echo "  make lint            - Run linter"
+	@echo "  make format          - Format code"
+	@echo "  make clean           - Clean build artifacts"
+	@echo ""
+	@echo "Maintenance:"
+	@echo "  make uninstall       - Uninstall SuperClaude components"
+	@echo "  make update          - Update SuperClaude components"
+	@echo ""
+	@echo "Documentation:"
+	@echo "  make translate       - Translate README to Chinese and Japanese (requires Ollama)"
+	@echo "  make help            - Show this help message"