fix(core): attempt compression before context overflow check (#16914)

packages/core/src/config/config.ts

@@ -490,6 +490,7 @@ export class Config {
   private readonly enablePromptCompletion: boolean = false;
   private readonly truncateToolOutputThreshold: number;
   private readonly truncateToolOutputLines: number;
+  private compressionTruncationCounter = 0;
   private readonly enableToolOutputTruncation: boolean;
   private initialized: boolean = false;
   readonly storage: Storage;
@@ -1585,6 +1586,8 @@ export class Config {
       return this.compressionThreshold;
     }
 
+    await this.ensureExperimentsLoaded();
+
     const remoteThreshold =
       this.experiments?.flags[ExperimentFlags.CONTEXT_COMPRESSION_THRESHOLD]
         ?.floatValue;
@@ -1766,6 +1769,10 @@ export class Config {
     return this.truncateToolOutputLines;
   }
 
+  getNextCompressionTruncationId(): number {
+    return ++this.compressionTruncationCounter;
+  }
+
   getUseWriteTodos(): boolean {
     return this.useWriteTodos;
   }