Add real media-file probing (session 9, sixteenth delivery)

Wires real container-header probing into the Rename panel's Match step, the
first item on the porting roadmap: aurora-curator-core::probe reads actual
resolution, frame rate, duration, and video/audio codecs straight from a
file's own header (mp4 crate for MP4/M4V/MOV, matroska crate for MKV/WebM,
no ffmpeg/MediaInfo dependency), batched through a new probe_media_files
Tauri command. Probed values fill {resolution}/{video codec}/{audio codec}
only when a filename release tag hasn't already, and populate five bindings
with no filename-tag equivalent at all: {width}, {height}, {fps},
{duration}, {file size}. 8 new Rust unit tests against real ffmpeg-generated
fixture files (161 -> 169 total), verified end to end with a 15-check
Playwright script against npm run dev, and README updated (status
paragraph, project layout, a new "Real media-file probing" section, and
roadmap item 1 narrowed to what's still missing).

src-tauri/src/lib.rs

@@ -5,6 +5,7 @@ mod history;
 mod list;
 mod metadata;
 mod presets;
+mod probe;
 mod settings;
 mod sfv;
 mod subtitles;
@@ -47,11 +48,13 @@ fn guess_movie(filename: String) -> Option<MovieGuess> {
 
 /// Guesses release-tag metadata (resolution, source, video/audio codec, release
 /// group) from a filename's own text using local regex patterns only - no network
-/// calls, no real media probing (Aurora Curator never ships an ffprobe/MediaInfo dependency,
-/// so filename tags are the only source for these fields). Independent of
-/// `guess_episode`/`guess_movie`: called alongside whichever of those two applies,
-/// since a release name carries (or doesn't carry) these tags regardless of whether
-/// it's an episode or a movie.
+/// calls, no file I/O. Complements `probe::probe_media_files` below, which reads the
+/// same kind of resolution/codec data straight from a file's real container header
+/// instead of guessing it from filename text - the Rename panel merges both,
+/// preferring an explicit filename tag over a probed value when a file has both.
+/// Independent of `guess_episode`/`guess_movie`: called alongside whichever of those
+/// two applies, since a release name carries (or doesn't carry) these tags regardless
+/// of whether it's an episode or a movie.
 #[tauri::command]
 fn guess_release_info(filename: String) -> Option<ReleaseInfo> {
     matching::guess_release_info(&filename)
@@ -123,6 +126,7 @@ pub fn run() {
             sfv::save_checksum_file,
             sfv::verify_checksum_file,
             list::export_text_list,
+            probe::probe_media_files,
             history::list_rename_history,
             history::undo_rename_batch,
             presets::list_presets,