Mixed libraries classify episodes in a TVDB-tagged show folder as a movie

[Quick104]

Problem

In a Mixed library, episodes in a show folder that has a {tvdb-…} tag but no season folder are classified as a movie. With Show (2024) {tvdb-12345}/Show S01E03.mkv and Show S01E04.mkv, both files become movies with the same movie group key (v1|movie|anchor|tvdb-12345), so the show turns into one movie instead of a series. The root is resolved with high confidence, so it doesn't appear under Ambiguous Roots. Only a folder with a single episode gets flagged as ambiguous. Sonarr's folder naming can add the show's TVDB ID, which produces this layout.

The Mixed classifier checks, in order: season folder, then movie-folder evidence, then an episode token. Any provider tag on the parent folder counts as movie-folder evidence, whatever the provider. Checking movie-folder evidence before the episode token is deliberate: a tagged movie whose title looks like an episode code must stay a movie (the "mixed library obvious movie folder beats episode token" case, which uses {imdb-…} {tmdb-…} tags). The question here is narrower: should a TVDB tag count as movie-folder evidence?

TVDB also lists movies, and Silo accepts a TVDB ID as a movie anchor (last in the movie precedence), so a TVDB tag doesn't prove a series.

I found this by reading the code and tests while auditing the docs for #1635, and confirmed it with a throwaway unit test calling ResolvePathContext, InferRootAssignments, and InferGroupIdentity. I didn't run a library scan.

Options

• Don't count a TVDB-only tag as movie-folder evidence. The file then falls through to the episode-token step, so episodes become series. A tagged movie with no episode-like name still defaults to movie. This is the smallest change. A folder that also carries a TMDB or IMDb tag keeps today's behavior.
• Treat a TVDB tag as series evidence when the file also has an episode token, even next to other tags. This covers Sonarr folders with several IDs, but it flips a movie whose title looks like an episode code if its folder carries a TVDB ID.
• Keep the current behavior and document that episodes in a Mixed library need a Season NN folder. docs: cover every folder and filename form Silo reads, Mixed classification, and Ambiguous Roots siloserver.org#41 asks the manual for that note.

For the first two options, pin the behavior with new cases:

• TestResolvePathContext: /mixed/Show (2024) {tvdb-12345}/Show S01E03.mkv → series; /mixed/Movie (2020) {tvdb-12345}/Movie (2020).mkv → movie.
• An InferRootAssignments plus InferGroupIdentity case with two episodes in a TVDB-tagged folder: expect series assignments and a series group, not one movie group.
• Keep "mixed library obvious movie folder beats episode token" unchanged.

Technical notes

• Classification order: ResolvePathContext, internal/naming/filename.go:80–88; extractPathEvidence, internal/naming/root_inference.go:308–316.
• Evidence: detectInferMovieFolderEvidence (internal/naming/root_inference.go:421) returns true for any ParseFolderIDs(parentBase) hit at line 425.
• Single-file ambiguity: the episode-token contradiction at root_inference.go:296, and the ObservedFileCount == 1 rule at line 175.
• Movie anchor precedence includes TVDB: movieProviderPrecedence, internal/contentid/contentid.go:92.
• Existing tests that keep the deliberate order: TestResolvePathContext ("mixed library obvious movie folder beats episode token", internal/naming/filename_test.go:423; "mixed library id tagged movie folder beats divergent release filename", line 570), TestParseFilename (line 168), and TestDetectSeriesRoot ("mixed library movie folder beats bare episode token", line 69).

AI disclosure

• Harness: T3 Code (Claude Code agent harness)
• Tool(s): Claude Code, GitHub CLI
• Model(s): claude-opus-5-5
• Involvement: AI-assisted; filed at the maintainer's request
• Adversarial review: n/a