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.

testing/probe_video.py

@@ -98,9 +98,9 @@ def main() -> None:
         print(c(f"Error: {path} does not exist", RED), file=sys.stderr)
         sys.exit(1)
 
-    from alfred.infrastructure.filesystem.ffprobe import probe
+    from alfred.infrastructure.probe import FfprobeMediaProber
 
-    info = probe(path)
+    info = FfprobeMediaProber().probe(path)
     if info is None:
         print(c("Error: ffprobe failed to probe the file", RED), file=sys.stderr)
         sys.exit(1)