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>

open-sse/translator/concerns/thinking.js

@@ -0,0 +1,29 @@
+// Concern: reasoning_effort ↔ provider-native thinking config.
+// Each provider expresses "how much to think" differently — centralize the maps here.
+// Streaming reasoning delta shape lives in reasoning.js; this file is request-side config only.
+
+// OpenAI reasoning_effort → Claude thinking.budget_tokens
+const EFFORT_TO_BUDGET = { none: 0, low: 4096, medium: 8192, high: 16384, xhigh: 32768 };
+
+// Returns budget_tokens for a reasoning_effort, or undefined if unknown effort.
+// 0 means "no thinking" (caller skips enabling); undefined means "effort not recognized".
+export function effortToBudget(effort) {
+  if (!effort) return undefined;
+  return EFFORT_TO_BUDGET[String(effort).toLowerCase()];
+}
+
+// OpenAI reasoning_effort → Gemini thinkingLevel (gemini-3 enum: minimal|low|medium|high).
+// Gemini 3 cannot fully disable thinking; "none"/"off" map to "minimal" (closest to off).
+export function effortToThinkingLevel(effort) {
+  const e = String(effort).toLowerCase().trim();
+  return e === "none" || e === "off" ? "minimal" : e;
+}
+
+// Gemini thinkingBudget (numeric) → OpenAI reasoning_effort (antigravity reverse map).
+// Returns null when budget <= 0 (no reasoning).
+export function budgetToEffort(budget) {
+  if (!budget || budget <= 0) return null;
+  if (budget <= 2048) return "low";
+  if (budget <= 16384) return "medium";
+  return "high";
+}