Treat inference hook denials as terminal errors (#60511)

## Why

An explicit denial from a workspace inference hook should stop the request, including retries and compaction model fallback.

## What changed

Recognize `inference_hook_denied` provider errors and preserve the provider's message, with a fallback when none is supplied. Expose the distinct `inferenceHookDenied` error through the app-server protocol and generated schemas and SDK types. Treat the denial as non-retryable during turns, compaction, and guardian review.

## Testing

Add coverage for terminal denials over HTTP, SSE, and WebSocket, error serialization and persistence in `thread/read`, and compaction failures that preserve token usage and history without retrying or falling back to another model.

GitOrigin-RevId: 2ebd480f01e52f4e6bd3db8a0f92d5814d18ccb1

codex-rs/app-server-protocol/schema/json/v2/ThreadReadResponse.json

@@ -130,6 +130,13 @@
           ],
           "type": "string"
         },
+        {
+          "description": "The workspace's inference hook explicitly denied this request.",
+          "enum": [
+            "inferenceHookDenied"
+          ],
+          "type": "string"
+        },
         {
           "additionalProperties": false,
           "properties": {