feat: implement LockfileManager with full CRUD operations

- Add LockfileManager class with read/write/update/validate methods
- Implement comprehensive lockfile validation (version, commit SHA, timestamps, configs)
- Add 30 comprehensive unit tests covering all lockfile operations
- Export core modules (GitManager, FileSystemManager, LockfileManager, validators)
- Fix FileNotFoundError prototype chain for proper instanceof checks
- Remove duplicate getLockfilePath from constants (keep in path-utils)
- All 88 tests passing

Author: lucaforni

README.md

@@ -459,20 +459,68 @@ npm run test:coverage
 
 ## 📊 Project Status
 
-**Current Phase**: Planning  
-**Target Release**: Phase 1 MVP - Q2 2026  
-**Status**: ✅ Specifications Complete
-
-### Roadmap
-
-- ✅ Phase 0: Specifications & Planning (Current)
-- ⏳ Phase 1: MVP Implementation (10 weeks)
-  - Core commands (init, sync, status, list, validate, update)
-  - Git-based versioning
-  - Auto-discovery
-  - Schema validation
-  - Namespace isolation
-  - Tag filtering
+**Current Phase**: Phase 1 MVP Implementation  
+**Target Release**: Q1 2026  
+**Status**: 🚧 In Active Development
+
+### Development Progress
+
+#### ✅ Completed (Weeks 1-2)
+
+**Week 1: Project Foundation**
+- ✅ TypeScript project setup with strict mode
+- ✅ Build pipeline (tsup) and testing (Vitest)
+- ✅ CLI framework with Commander.js
+- ✅ Core type system and error hierarchy
+- ✅ CI/CD pipelines (GitHub Actions)
+- ✅ 12 initial unit tests
+
+**Week 2: Core Modules**
+- ✅ GitManager: Full Git operations support
+- ✅ FileSystemManager: Complete file operations
+- ✅ Path utilities for cross-platform support
+- ✅ Zod schemas for all configuration types
+- ✅ Comprehensive validators (Agent, Skill, MCP, Manifest, Lockfile)
+- ✅ 58 unit tests passing (80%+ coverage on core modules)
+
+#### 🚧 In Progress (Week 3)
+
+**Week 3-4: CLI Commands Part 1**
+- 🚧 `oct init` command implementation
+- 🚧 Lockfile management
+- 📋 `oct sync` command
+
+#### 📋 Upcoming
+
+**Week 5-6: CLI Commands Part 2**
+- `oct status`, `oct list`, `oct validate`
+- `oct update`, `oct rollback`
+- `oct remove`, `oct clean`, `oct info`
+
+**Week 7-8: Advanced Features**
+- Auto-discovery engine
+- Tag filtering system
+- Namespace isolation manager
+- Error handling refinements
+
+**Week 9-10: Testing & Release**
+- Integration tests
+- Performance testing
+- Documentation
+- Beta release
+
+See [ROADMAP.md](ROADMAP.md) for detailed timeline and task breakdown.
+
+### Test Coverage
+
+- **58 unit tests passing**
+- Core modules: 80%+ coverage
+- Type checking: ✅ Passing
+- Linting: ✅ Passing
+- Build: ✅ Successful
+
+### Future Phases
+
 - 🔮 Phase 2: Enhanced Features
   - Multiple team config sources
   - Interactive TUI mode
@@ -481,8 +529,6 @@ npm run test:coverage
   - Plugin system
   - Web dashboard (optional)
 
-See [ROADMAP.md](ROADMAP.md) for detailed timeline.
-
 ---
 
 ## 🔒 Security