refactor(probe): consolidate full probe() into MediaProber port

Add probe(video) -> MediaInfo | None to the MediaProber Protocol and
implement it on FfprobeMediaProber. The standalone
alfred/infrastructure/filesystem/ffprobe.py module is removed; all
callers (analyze_release / probe_media tools, testing scripts) now go
through the adapter.

Tests for the probe path moved to tests/infrastructure/test_ffprobe_prober.py
(patching subprocess.run at the adapter module level).

Unblocks the upcoming inspect_release orchestrator, which needs the
port — not a free function — to compose parse + main-video selection
+ probe in one shot.

CHANGELOG.md

@@ -15,6 +15,23 @@ callers).
 
 ## [Unreleased]
 
+### Changed
+
+- **`MediaProber` port now covers full media probing**: added
+  `probe(video) -> MediaInfo | None` alongside the existing
+  `list_subtitle_streams`. `FfprobeMediaProber` (in
+  `alfred/infrastructure/probe/`) implements both methods and is now
+  the single adapter shelling out to `ffprobe`. The standalone
+  `alfred/infrastructure/filesystem/ffprobe.py` module was removed —
+  all callers (tools, testing scripts) instantiate
+  `FfprobeMediaProber` instead. Unblocks the upcoming
+  `inspect_release` orchestrator, which depends on the port.
+
+### Removed
+
+- `alfred/infrastructure/filesystem/ffprobe.py` (folded into the
+  `FfprobeMediaProber` adapter).
+
 ---
 
 ## [2026-05-20] — Release parser confidence scoring + exclusion