Major refactoring to support persistent box state with stop/restart capabilities.

## Core Changes

### Database Persistence
- Add SQLite-based box state storage (db/boxes.rs, db/schema.rs)
- Persist BoxConfig and BoxState across runtime restarts

### Box Lifecycle Management
- Add BoxManager with state machine (Starting → Running → Stopped → Crashed)
- Implement stop(), restart, and reattach operations
- Add auto_remove option (like Docker --rm) for automatic cleanup

### Container Init Process
- Add stdio pipes to keep container init alive (guest/container/stdio.rs)
- Replace sleep infinity workaround with pipe-based blocking

### Architecture
- Refactor init stages to tasks-based pipeline
- Move controller to vmm/controller module
- Add BoxBuilder for lazy initialization
- Consolidate runtime types and state management

### SDK Updates
- Expose auto_remove in Python BoxOptions
- Update C SDK headers
- Add lifecycle example scripts

- Add auto_remove field to BoxOptions with manual Default impl
- Python SDK uses Option<bool> to inherit Rust default when None
- All Python box classes (SimpleBox, CodeBox, BrowserBox, ComputerBox,
  InteractiveBox) default to auto_remove=True (ephemeral)
- Low-level Rust BoxOptions defaults to false (persistent for debugging)

- Add optional user-defined name for boxes (unique, stored in BoxConfig)
- Support get/remove by ID or name (name lookup as fallback)
- Add name validation to prevent duplicates on create
- Add InvalidArgument error variant for validation errors

Refactor BoxliteRuntime to thin facade pattern:
- Move all implementation to RuntimeInnerImpl (rt_impl.rs)
- BoxliteRuntime delegates to self.inner for all operations
- Enables LiteBox to call runtime methods directly via RuntimeInner

Python SDK updates:
- Add name parameter to create(), SimpleBox, InteractiveBox
- Add name property to Box handle
- Update get/remove to accept id_or_name

Signed-off-by: dorianzheng <xingzhengde72@gmail.com>

- Add missing 'name: None' field to BoxConfig in test files
- Change &PathBuf to &Path in vmm_spawn.rs
- Implement FromStr trait for BoxStatus instead of inherent from_str method
- Allow clippy::module_inception for pipeline module
- Update lifecycle tests to use new create() signature with name parameter