🤖 fix: preserve openai reasoning replay ids (#17792)

What:
- disable tool-call id sanitization for OpenAI/OpenAI Codex transcript policy
- gate id sanitization in image sanitizer to full mode only
- keep orphan reasoning downgrade scoped to OpenAI model-switch replay path
- update transcript policy, session-history, sanitizer, and reasoning replay tests
- document OpenAI model-switch orphan-reasoning cleanup behavior in transcript hygiene reference

Why:
- OpenAI Responses replay depends on canonical call_id|fc_id pairings for reasoning followers
- strict id rewriting in OpenAI path breaks follower matching and triggers rs_* orphan 400s
- limiting scope avoids behavior expansion while fixing the identified regression

Tests:
- pnpm vitest run src/agents/transcript-policy.test.ts src/agents/pi-embedded-runner.sanitize-session-history.test.ts src/agents/openai-responses.reasoning-replay.test.ts
- pnpm vitest run --config vitest.e2e.config.ts src/agents/transcript-policy.e2e.test.ts src/agents/pi-embedded-runner.sanitize-session-history.e2e.test.ts src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.e2e.test.ts src/agents/pi-embedded-helpers.sanitizeuserfacingtext.e2e.test.ts
- pnpm lint
- pnpm format:check
- pnpm check:docs
- pnpm test (fails in current macOS bash 3.2 env at test/git-hooks-pre-commit.integration.test.ts: mapfile not found)

src/agents/pi-embedded-helpers/images.ts

@@ -51,9 +51,10 @@ export async function sanitizeSessionMessagesImages(
   const allowNonImageSanitization = sanitizeMode === "full";
   // We sanitize historical session messages because Anthropic can reject a request
   // if the transcript contains oversized base64 images (see MAX_IMAGE_DIMENSION_PX).
-  const sanitizedIds = options?.sanitizeToolCallIds
-    ? sanitizeToolCallIdsForCloudCodeAssist(messages, options.toolCallIdMode)
-    : messages;
+  const sanitizedIds =
+    allowNonImageSanitization && options?.sanitizeToolCallIds
+      ? sanitizeToolCallIdsForCloudCodeAssist(messages, options.toolCallIdMode)
+      : messages;
   const out: AgentMessage[] = [];
   for (const msg of sanitizedIds) {
     if (!msg || typeof msg !== "object") {