fix(shared): restrict cached Anthropic 1M context to GA 4.6 models only

src/shared/context-limit-resolver.ts

@@ -1,6 +1,12 @@
 import process from "node:process"
 
 const DEFAULT_ANTHROPIC_ACTUAL_LIMIT = 200_000
+const ANTHROPIC_NO_HEADER_GA_MODEL_IDS = new Set([
+  "claude-opus-4-6",
+  "claude-opus-4.6",
+  "claude-sonnet-4-6",
+  "claude-sonnet-4.6",
+])
 
 export type ContextLimitModelCacheState = {
   anthropicContext1MEnabled: boolean
@@ -20,6 +26,10 @@ function getAnthropicActualLimit(modelCacheState?: ContextLimitModelCacheState):
     : DEFAULT_ANTHROPIC_ACTUAL_LIMIT
 }
 
+function isAnthropicNoHeaderGaModel(modelID: string): boolean {
+  return ANTHROPIC_NO_HEADER_GA_MODEL_IDS.has(modelID.toLowerCase())
+}
+
 export function resolveActualContextLimit(
   providerID: string,
   modelID: string,
@@ -30,7 +40,7 @@ export function resolveActualContextLimit(
     if (explicit1M === 1_000_000) return explicit1M
 
     const cachedLimit = modelCacheState?.modelContextLimitsCache?.get(`${providerID}/${modelID}`)
-    if (cachedLimit) return cachedLimit
+    if (cachedLimit && isAnthropicNoHeaderGaModel(modelID)) return cachedLimit
 
     return DEFAULT_ANTHROPIC_ACTUAL_LIMIT
   }