refactor(app): DRY pass — split large files, extract shared utils
S1: delete page.new.js (1724L abandoned) + remove dead getAntigravityProjectId
S2: split large files by natural seams
- usage.js → usage/{github,google,claude,codex,kiro,minimax,misc,shared}.js
- media-providers page → components/{Embedding,Tts,Generic,Stt}ExampleCard.js
- EndpointPageClient → endpointConstants.js + endpointPing.js + components/
- tokenRefresh.js → tokenRefresh/{dedup,providers}.js
- ProviderLimits/index.js: 16 pure fn + 9 constants → utils.js
- oauth/providers.js: 7 pure helpers → providerHelpers.js
S3: shared utils
- getModelKind(m, fallback) → shared/constants/models.js (replaces 20× m.kind||m.type)
- getStatusVariant → shared/utils/connectionStatus.js (dedup ConnectionRow/ConnectionsCard)
- sseChunk → open-sse/utils/sse.js (dedup grok-web/perplexity-web)
- fetchWithTimeout → usage/shared.js (replace 4× AbortController pattern in google.js)
fix: enableObservability2 field name in requestDetailsRepo
Co-authored-by: Cursor <cursoragent@cursor.com>
fbf973f2e7