gallery: remove duplicated entries and lint against them recurring

[localai-bot]

What this does

Removes 8 duplicated entries from gallery/index.yaml and adds the lint rules that keep them out.

FindGalleryElement returns the first match, so the second copy of a duplicated name was never reachable. Each pair is byte-identical apart from position, verified two independent ways (parsed comparison with merge keys resolved and canonically serialised, and a raw-text byte comparison of the blocks), so removing the second copy changes no behaviour at all.

Removed: deepseek-r1-distill-llama-8b, llama3.2-3b-enigma, qwen3-asr-0.6b, qwen3-asr-1.7b, qwopus-glm-18b-merged, voice-en-us-kathleen-low, whisper-large-q5_0, whisper-small-q5_1.

The diff is pure deletions: 0 insertions, 212 deletions.

Why it matters beyond tidiness

A variant reference to a duplicated name is ambiguous, since it is not clear which declaration it points at. The proposal job in #10992 already refuses to propose against these names for exactly that reason, and whisper-large-q5_0 and whisper-small-q5_1 are both in whisper families that would otherwise be grouped.

Two lint rules

Duplicate entry names. Reports the name and explains that only the first declaration is reachable, so the later one is dead weight.

Doubly-claimed variant targets. VariantParents in core/gallery/collapse_variants.go resolves a build claimed by two parents by taking the first in gallery order, and its comment justifies that arbitrary tiebreak by saying it keeps the listing deterministic "for a gallery the linter would reject". The linter did not reject it. That comment is now true.

The second rule sits beside the first rather than in its own change, because it is a variant invariant belonging next to the rule it complements, and splitting it would leave that comment describing a linter that does not exist for no reviewing benefit. It mirrors what VariantParents actually skips (dangling, nested and self references), so it does not double-report breaches checkVariantReferences already owns. One parent listing the same target twice is not a violation. Green on arrival: no target is doubly claimed today, by curation rather than by rule.

Verification

Both rules proven red before green:

voice-en-us-kathleen-low: entry "voice-en-us-kathleen-low" is declared more than once:
FindGalleryElement returns the first match, so only the first declaration is
reachable and this one is dead weight

lint-red-proof-second-parent -> variant "ternary-bonsai-8b-q2-g64":
already offered as a variant by "ternary-bonsai-8b"

Entries 1282 to 1274, exactly 8 lost, all 1274 names now unique. A resolved-entry diff confirms no surviving entry has any changed field, and no name was lost or gained beyond the removals. No dangling variant references afterwards.

Anchor check: all 16 blocks were scanned for anchor definitions and merge references before deleting. None of the sixteen defines an anchor or pulls one in; the index's real anchors all sit on entries outside every duplicated pair. Deleting the wrong copy of an anchored entry would have broken its merging children, so this was checked rather than assumed.

core/gallery 324 specs pass, core/gallery/importers and core/http/routes ok, make lint 0 issues, build and vet and gofmt clean.

Assisted-by: Claude:claude-opus-4-8 [Claude Code]