refactor(providers): extract metadata providers into modular system

- Create `unshackle/core/providers/` package with abstract base class, IMDBApi (free, no key), SIMKL, and TMDB provider implementations
- Add consensus-based ID enrichment: cross-references IMDB IDs with TMDB and SIMKL, drops all data from providers that disagree on tmdb_id (likely resolved to wrong title)
- Cache enriched IDs alongside raw provider data so they survive cache round-trips
- Genericize TitleCacher with `cache_provider()`/`get_cached_provider()` replacing provider-specific methods; respect `--no-cache` flag
- Add `--imdb` CLI flag to dl command for direct IMDB ID lookup

.pre-commit-config.yaml

@@ -7,10 +7,10 @@ repos:
     hooks:
       - id: conventional-pre-commit
         stages: [commit-msg]
-  - repo: https://github.com/mtkennerly/pre-commit-hooks
-    rev: v0.4.0
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.11.3
     hooks:
-      - id: poetry-ruff-check
+      - id: ruff
         args: [--fix]
   - repo: https://github.com/pycqa/isort
     rev: 6.0.1