BREAKING CHANGE: Python's RestOptions is now BoxliteRestOptions to
match the Rust implementation and follow consistent naming conventions.

Why:
- Rust uses BoxliteRestOptions, Python exposed RestOptions (inconsistent)
- RestOptions is too generic and may cause namespace collisions
- Follows project pattern: runtime-level configs use Boxlite*Options prefix
- Exception: Options (primary config) remains as-is (justified singleton)

Impact:
- Affects all REST API examples (7 files)
- Clean failure mode: ImportError for old name (type-safe)
- Low risk: REST API just landed, no production users yet

Migration:
```python
# Before (v0.4.4)
from boxlite import RestOptions
opts = RestOptions(url="http://localhost:8080")

# After (v0.5.0)
from boxlite import BoxliteRestOptions
opts = BoxliteRestOptions(url="http://localhost:8080")
```

Changed:
- Core SDK (3 files):
  - sdks/python/src/options.rs - pyclass name, docstrings, __repr__
  - sdks/python/boxlite/__init__.py - import and export names
  - sdks/python/src/runtime.rs - docstring examples
- Examples (7 files):
  - All files in examples/python/08_rest_api/ - imports and constructors
- Documentation (1 file):
  - examples/python/08_rest_api/README.md - description

Verification:
✓ make dev:python builds successfully
✓ from boxlite import BoxliteRestOptions works
✓ from boxlite import RestOptions raises ImportError
✓ All examples tested and passing
✓ Docstrings show BoxliteRestOptions

- Fix collapsible_if in rest/runtime.rs (use && for nested if-let)
- Fix redundant_closure in rest/types.rs (use BoxID::new directly)
- Apply cargo fmt to all REST API code

These fixes resolve CI failures caused by clippy warnings.

Files changed: 10 files (REST API and Python SDK)

Replace .unwrap_or_else(BoxID::new) with .unwrap_or_default() in
boxlite/src/rest/types.rs:140.

This is more idiomatic Rust since BoxID implements Default trait.
The behavior is functionally equivalent as Default::default() delegates
to Self::new().

Resolves clippy::unwrap_or_default warning.

Separates image operations from RuntimeBackend into a dedicated ImageHandle
abstraction, following the same pattern as LiteBox for box operations.

Changes:
- Created ImageManager trait and ImageHandle struct for image operations
- LocalRuntime implements ImageManager (pull_image, list_images)
- REST runtime returns None for image_manager (unsupported)
- BoxliteRuntime.images() returns ImageHandle or error
- Removed image methods from RuntimeBackend trait
- Updated CLI commands to use runtime.images().pull() pattern
- Removed REST image types and endpoints from reference server
- Exported ImageHandle in lib.rs

Benefits:
- Consistent API pattern (runtime → handle → operations)
- Type-safe: REST runtime can't expose unsupported operations
- Clean separation: images are separate domain from runtime management
- Extensible: easy to add more image operations to handle

Refs: Plan at ~/.claude/plans/immutable-napping-blum.md

During the ImageHandle refactoring, we incorrectly changed the return
type from ImageObject to ImageInfo, breaking the CLI's method-based API.

Changes:
- ImageHandle::pull() now returns ImageObject (handle with methods)
- ImageHandle::list() still returns Vec<ImageInfo> (display metadata)
- CLI pull command restored to use methods: config_digest(), reference(), layer_count()
- Removed unnecessary to_info() conversion in LocalRuntime

This restores the correct abstraction:
- Pull → ImageObject (working handle)
- List → Vec<ImageInfo> (display data)

Removed two unused methods from ImageObject:
- manifest_digest(): Never used, already marked #[allow(dead_code)]
- to_info(): Added during REST API implementation when RuntimeBackend
  returned ImageInfo, but no longer needed after separating image
  operations into ImageManager trait

These methods were leftovers from the REST API refactoring and serve
no current purpose. Removing them follows YAGNI principle and keeps
the codebase clean.

Verified with:
- git grep '\.to_info\(\)|\.manifest_digest\(\)' → no results
- cargo build && cargo clippy → no errors

Aligns Rust internal type name with the exported Python class name
(BoxliteRestOptions) for better consistency and maintainability.

This follows the established naming convention where Rust types reflect
their Python exports:
- PyBoxOptions → BoxOptions
- PyCopyOptions → CopyOptions
- PyBoxlite → Boxlite
- PyBoxliteRestOptions → BoxliteRestOptions (now consistent)

Changes:
- sdks/python/src/options.rs: Renamed struct and implementations
- sdks/python/src/runtime.rs: Updated import and method parameter
- sdks/python/src/lib.rs: Updated import and module export

No changes to Python API - BoxliteRestOptions remains the same for users.

Reorder imports alphabetically per Rust style guidelines.