fix(core,server,web,cli): compaction tolerance, retry parity, and failure classification (#174)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/core/test/describe-image.test.ts

@@ -177,7 +177,7 @@ describe("describe_image (the text-only-model variant of read_image)", () => {
 
   it("vision model request failure: failed with the status and message", async () => {
     await writeFile(path.join(tmp, "a.png"), PNG_1X1);
-    const { llm } = fakeLLM("", { status: "failed", message: "401 unauthorized" });
+    const { llm } = fakeLLM("", { status: "failed", errorMessage: "401 unauthorized" });
     const { result, text } = await run({ source: "a.png" }, tmp, {
       modelId: "vis-1",
       createLLM: () => llm,