test: fix azure msg-id preservation and retry-diagnostics log shape

Second upstream merge (upstream/main advanced 24 more commits) pulled
in two independent behavior changes that broke tests I'd already
touched or that existed:

- packages/ai: commits cda6df81d/d7f070d44 added
  preserveAssistantMessageIds for Azure specifically (azure sets it
  true), so the earlier fix stripping msg ids in
  azure-openai-responses-stream.test.ts is now wrong for Azure — it
  should preserve them, unlike the plain OpenAI path. Restored the
  id/phase assertions and renamed both tests to describe the
  preserve-not-omit contract.

- packages/coding-agent: commit 0e2feab74 (refactor: reduced session
  log footprint) deleted the
  '#agentContinueState'/'agent.continue failed state after
  scheduling' debug diagnostics and changed
  'agent active context assistant removal' to fire only on a miss,
  renamed to 'agent active context assistant removal missed' with a
  smaller payload (no more removed/beforeLength/afterLength/etc).
  agent-session-retry-diagnostics.test.ts still asserted the old
  shape and waited on a debug call that no longer exists, so it hung
  for the full 5s timeout. Updated to match the new log name/payload
  and dropped the removed diagnostic assertion; the retry-recovery
  behavior itself is unchanged and still exercised end to end.

packages/coding-agent/test/agent-session-retry-diagnostics.test.ts

@@ -74,11 +74,11 @@ async function waitFor(predicate: () => boolean, timeoutMs = 500): Promise<void>
 function isRemovalMissDebugCall(call: unknown[]): boolean {
 	const payload = call[1];
 	return (
-		call[0] === "agent active context assistant removal" &&
+		call[0] === "agent active context assistant removal missed" &&
 		typeof payload === "object" &&
 		payload !== null &&
-		"removed" in payload &&
-		payload.removed === false
+		"reason" in payload &&
+		payload.reason === "auto-retry"
 	);
 }
 
@@ -143,15 +143,10 @@ describe("AgentSession retry diagnostics", () => {
 
 		const promptPromise = session.prompt("trigger transient error").catch(() => undefined);
 		await waitFor(() => debugSpy.mock.calls.some(isRemovalMissDebugCall));
-		await waitFor(() => debugSpy.mock.calls.some(call => call[0] === "agent.continue failed state after scheduling"));
 
 		expect(debugSpy.mock.calls).toContainEqual([
-			"agent active context assistant removal",
-			expect.objectContaining({ reason: "auto-retry", removed: false, lastRole: "assistant" }),
-		]);
-		expect(debugSpy.mock.calls).toContainEqual([
-			"agent.continue failed state after scheduling",
-			expect.objectContaining({ lastRole: "assistant", messageCount: 2 }),
+			"agent active context assistant removal missed",
+			expect.objectContaining({ reason: "auto-retry", lastRole: "assistant" }),
 		]);
 		await session.abort();
 		await promptPromise;