fix(api): alias-backed models leak raw node UUID prefix in /v1/models (#8958)

[Rahulsharma0810]

Summary

Fixes #8958. For an OpenAI-/Anthropic-compatible provider node with a custom prefix (node id is a UUID), GET /v1/models listed every alias-backed model twice: the correct prefix/model id and a duplicate raw <node-uuid>/model id — even under MODELS_CATALOG_PREFIX_MODE=alias.

Root cause

The alias-backed models loop (added in #4630) in src/app/api/v1/models/catalog.ts built its display prefix without consulting providerIdToPrefix:

const alias = providerIdToAlias[canonicalProviderId] || providerKey;

For a compatible node, canonicalProviderId is the UUID and providerIdToAlias[<uuid>] is undefined, so alias fell through to the raw UUID providerKey. The dedupe only compared alias/model and providerKey/model (both UUID-prefixed), so it never matched the correct prefix/model row already emitted by the synced-models loop. Additionally, the includeCanonical branch pushed ${canonicalProviderId}/${modelId} (= <uuid>/model) in default/dual modes — a second leak.

The synced-models (catalog.ts:896) and custom-models (catalog.ts:1245) loops already handle this correctly via const prefix = providerIdToPrefix[...] and a && !prefix guard on their canonical push. owned_by was also already masked by resolvePublicOwnerId (#8327) — only the published id leaked.

Fix

Mirror the sibling loops in the alias-backed block:

const nodePrefix = providerIdToPrefix[providerKey] || providerIdToPrefix[canonicalProviderId];
const alias = nodePrefix || providerIdToAlias[canonicalProviderId] || providerKey;

and add && !nodePrefix to the includeCanonical emit guard. The id collapses to prefix/model, which the existing dedupe skips; the canonical UUID row is no longer emitted for prefixed nodes.

Tests

Adds tests/unit/8958-alias-backed-node-prefix.test.ts (real-DB harness, same style as the #8327 test):

• alias mode: exactly one prefix/model, no UUID-prefixed id anywhere
• default and dual modes: prefix/model present, no <node-uuid>/… id

Verified locally:

• new test: 2/2 pass
• sibling 8327-models-owned-by-prefix.test.ts: 3/3 pass
• models-catalog-route, models-catalog-hide-paid, catalog-helpers-extraction, cc-compatible-model-catalog, model-alias-provider-resolution: 69/69 pass

Also validated against a live instance running the equivalent patch: ?prefix=alias and default/dual drop the duplicate UUID entries while retaining the correct prefix/ rows; ?prefix=canonical is unchanged; routing via both the alias and the prefix/… id is unaffected.