feat(v2.0.0): migrate to Claude Code v2.1.4+ architecture

Major architectural update to support Claude Code v2.1.4+ features including
hooks, modern permission syntax, and hot-reload capabilities.

## Core Component Updates

### Skill (skill/SKILL.md)
- Updated frontmatter from old `tools:` to `permissions.allow:` array
- Added wildcard Bash permissions: Bash(ls:*), Bash(find:*), Bash(git:*)
- Python modules unchanged (backward compatible)

### Command (command/enhance-claude-md.md)
- Updated frontmatter from `allowed-tools:` to `permissions.allow:` array
- Added startup hook for workflow initiation
- 3-phase discovery workflow unchanged

### Guardian Agent (agent/claude-md-guardian.md)
- Updated frontmatter from `tools:` to `permissions.allow:` array
- Added SessionStart hook for auto-updates on new sessions
- Added PreToolUse/PostToolUse hooks for Write validation
- Added fork_safe: true for independent operation
- Removed obsolete mcp_tools field
- Agent workflow logic unchanged

## Installation Scripts

### install.sh
- Added Claude Code version detection (checks for 2.1.0+)
- Added auto-migration logic with timestamped backups
- Added post-installation v2.1.4 compatibility validation
- Updated version to 2.0.0
- Updated download URLs to main branch

### install.ps1
- Added equivalent PowerShell version detection
- Added auto-migration logic with timestamped backups
- Added post-installation v2.1.4 compatibility validation
- Updated version to 2.0.0
- Updated download URLs to main branch

## Documentation

### New Files
- docs/MIGRATION_V2.md: Comprehensive migration guide
- test/validate_migration.sh: Validation script (18 tests)
- test/rollback.sh: Rollback script for v1.x restoration
- test/README.md: Testing documentation

### Updated Files
- README.md: Updated version badges (2.0.0, Claude Code 2.1.4+)
- README.md: Added "New in v2.0" section highlighting features
- CHANGELOG.md: Added comprehensive v2.0.0 release entry
- CHANGELOG.md: Documented all changes, fixes, and breaking changes

## Validation

All changes validated:
✓ Python modules compile without errors
✓ install.sh bash syntax valid
✓ YAML frontmatter syntax valid (skill, command, agent)
✓ No Python code modified (2,190 lines unchanged)
✓ Backward compatible with existing installations

## Breaking Changes

- Minimum Claude Code version: 2.1.0+ (was 2.0+)
- Old permission syntax deprecated (but backward compatible)
- Users on Claude Code < 2.1.0 should use ClaudeForge v1.0.0

## Migration Path

Installer automatically:
1. Detects Claude Code version
2. Backs up v1.x installations
3. Installs v2.0 with new syntax
4. Validates compatibility

See docs/MIGRATION_V2.md for detailed instructions.

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

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

command/enhance-claude-md.md

@@ -1,6 +1,18 @@
 ---
-allowed-tools: Bash(ls:*), Bash(find:*), Bash(git status:*), Read, Glob, Skill
 description: Initialize or enhance CLAUDE.md files using the claude-md-enhancer skill with interactive workflow and 100% native format compliance
+permissions:
+  allow:
+    - Bash(ls:*)
+    - Bash(find:*)
+    - Bash(git status:*)
+    - Read
+    - Glob
+    - Skill
+hooks:
+  - matcher: ""
+    once: true
+    commands:
+      - echo "Starting CLAUDE.md enhancement workflow"
 ---
 
 # CLAUDE.md Enhancer Command