refactor(open-sse): translator DRY + schema enums, bug fixes, dead code cleanup

- Bug B1-B7: media UI m.kind||m.type, serviceKinds, gemini mediaPriority, schema kind, models/info lookup by kind
- Dead code D1-D6: safeParseJSON, drop PROVIDER_ENDPOINTS, orphan fetcher, GITHUB_CONFIG derive, getProviderConfig internal, legacy kiro file
- Translator concerns: toOpenAIUsage, toOpenAIFinish (gemini/kiro/ollama + fix kiro tool finish), thinking effort maps
- Reorg helpers/ → concerns/ (logic) + formats/ (per-format) + schema/ (pure enums: roles/blocks/finishReasons/defaults)
- Wire ~280 hardcoded role/block/finish/default literals to schema enums across 20+ files
- collapseTextParts + extractTextContent dedup
- Normalize translator fn names to openaiToXRequest / xToOpenAIResponse
- Golden tests lock behavior; 0 regression (byte-for-byte providers/alias, 26=26 known fails)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/shared/constants/providers.js

@@ -11,7 +11,6 @@ const MEDIA_ENTRY_KEYS = [
 // Build provider UI object from registry entry
 function buildProviderEntry(r) {
   const mediaFields = {};
-  // Support both legacy r.media wrapper and new flat top-level fields (post-migration)
   if (r.media) Object.assign(mediaFields, r.media);
   for (const k of MEDIA_ENTRY_KEYS) {
     if (r[k] !== undefined) mediaFields[k] = r[k];
@@ -21,6 +20,8 @@ function buildProviderEntry(r) {
     id: r.id,
     alias: r.uiAlias || r.alias,
     ...mediaFields,
+    ...(r.priority !== undefined ? { priority: r.priority } : {}),
+    ...(r.hasFree ? { hasFree: true } : {}),
     ...(r.thinkingConfig ? { thinkingConfig: r.thinkingConfig } : {}),
     ...(r.regions ? { regions: r.regions, defaultRegion: r.defaultRegion } : {}),
     ...(r.hasProviderSpecificData ? { hasProviderSpecificData: true } : {}),
@@ -147,7 +148,7 @@ export function getProvidersByKind(kind) {
       if (p.hiddenKinds?.includes(kind)) return false;
       return true;
     })
-    .sort((a, b) => (a.mediaPriority ?? 100) - (b.mediaPriority ?? 100));
+    .sort((a, b) => (a.priority ?? a.mediaPriority ?? 999) - (b.priority ?? b.mediaPriority ?? 999));
 }
 
 // Derive từ registry features flags