Return the prompt hash in upload responses (#44325)

## What changed

Add nullable `promptHash` to the upload response, populated from the uploaded `prompt_hash` tag. It identifies the whitespace-normalized SHA-256 of the session base instructions, excludes later developer messages, and is `null` when the reported rollout has no prompt metadata.

Update the protocol schemas, precomputed exports, and generated TypeScript and Python types.

GitOrigin-RevId: 6fa70fbe7a06604ac1cd0ea363eb4f192083dad9

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -11502,6 +11502,14 @@
       "FeedbackUploadResponse": {
         "$schema": "http://json-schema.org/draft-07/schema#",
         "properties": {
+          "promptHash": {
+            "default": null,
+            "description": "Whitespace-normalized SHA-256 of the session base instructions, matching the uploaded `prompt_hash` tag. Does not include later developer messages. Null when the reported rollout has no prompt metadata.",
+            "type": [
+              "string",
+              "null"
+            ]
+          },
           "threadId": {
             "type": "string"
           }