refactor(application): inject kb/prober into resolve_destination use cases

Remove the module-level _KB / _PROBER singletons from
alfred/application/filesystem/resolve_destination.py. The four
resolve_{season,episode,movie,series}_destination use cases now take
kb: ReleaseKnowledge and prober: MediaProber as required arguments,
matching the shape of inspect_release.

The singletons now live at the agent-tools frontier
(alfred/agent/tools/filesystem.py), where the LLM-facing wrappers
instantiate YamlReleaseKnowledge / FfprobeMediaProber once and thread
them through. The wrappers' Python signatures are unchanged — the
inspect-based JSON-schema generator in agent/registry.py still sees the
same LLM-passable params.

analyze_release drops the dirty 'from ... import _KB' indirection.

Tests inject their own stubs by keyword (prober=_StubProber(...)) via
thin convenience wrappers, replacing the prior
monkeypatch.setattr(rd, '_PROBER', ...) pattern.

testing/debug_release.py: instantiate YamlReleaseKnowledge() /
FfprobeMediaProber() inline at the two call sites.

Suite: 1077 passed.

CHANGELOG.md

@@ -57,6 +57,21 @@ callers).
 
 ### Changed
 
+- **`resolve_destination` use cases take `kb` / `prober` as required
+  params; module-level singletons gone.** The four
+  `resolve_{season,episode,movie,series}_destination` use cases now
+  accept `kb: ReleaseKnowledge` and `prober: MediaProber` as required
+  arguments, matching the shape of `inspect_release`. The module-level
+  `_KB = YamlReleaseKnowledge()` and `_PROBER = FfprobeMediaProber()`
+  singletons that previously lived in
+  `alfred/application/filesystem/resolve_destination.py` are removed —
+  the application layer no longer reaches into infrastructure. The
+  singletons now live at the agent-tools frontier
+  (`alfred/agent/tools/filesystem.py`), where the LLM-facing wrappers
+  instantiate them once and thread them through. `analyze_release` no
+  longer needs the dirty `from ... import _KB` indirection. Tests
+  inject their own stubs by keyword (`prober=_StubProber(...)`) instead
+  of monkeypatching a module attribute.
 - **`ParsePath` enum renamed to `TokenizationRoute`.** The old name
   collided with `pathlib.Path` in code-reading mental models, and was
   one letter from `parse_path` (the field that holds the value) — making