chore(cli): drop dead classifiers and single-use wrappers left by fallback removal (#112191)

Follow-up to c5254f13ee (#112074): delete the legacy string-match timeout
classifier (the CLI path only sees typed GatewayTransportError from
callGateway's wrapper timer), the duplicate JSON/blank-message validation
in the private gateway command, the now-pointless getGatewayDispatchConfig
wrapper, the single-use embedded-loader alias, and the cross-os release
guard for the EMBEDDED FALLBACK marker no build can emit anymore.

scripts/lib/cross-os-release-checks/agent.ts

@@ -1,6 +1,6 @@
 import { randomUUID } from "node:crypto";
 import { appendFileSync } from "node:fs";
-import type { AgentOutputOptions, AgentTurnResult } from "./config.ts";
+import type { AgentOutputOptions } from "./config.ts";
 import { CROSS_OS_AGENT_TURN_OPTIONAL, CROSS_OS_AGENT_TURN_TIMEOUT_SECONDS } from "./config.ts";
 import { readLogTextTail } from "./logs.ts";
 
@@ -73,24 +73,11 @@ export function buildReleaseAgentTurnArgs(sessionId: string) {
 
 export function shouldRetryCrossOsAgentTurnError(error: unknown) {
   const message = error instanceof Error ? error.message : String(error);
-  return /Agent output did not contain the expected OK marker|Agent turn used embedded fallback instead of gateway|model idle timeout|did not produce a response before the model idle timeout|gateway request timeout for agent|Command timed out|timed out and could not be terminated cleanly|rate limit reached|rate_limit_exceeded|HTTP 429|HTTP 503|upstream connect error|disconnect\/reset before headers|connection timeout/u.test(
+  return /Agent output did not contain the expected OK marker|model idle timeout|did not produce a response before the model idle timeout|gateway request timeout for agent|Command timed out|timed out and could not be terminated cleanly|rate limit reached|rate_limit_exceeded|HTTP 429|HTTP 503|upstream connect error|disconnect\/reset before headers|connection timeout/u.test(
     message,
   );
 }
 
-export function agentTurnUsedEmbeddedFallback(
-  result: Pick<AgentTurnResult, "stdout" | "stderr">,
-  options: AgentOutputOptions = {},
-) {
-  const logText =
-    typeof options.logText === "string"
-      ? options.logText
-      : typeof options.logPath === "string"
-        ? readLogTextTail(options.logPath)
-        : "";
-  return /EMBEDDED FALLBACK:/u.test(`${result.stdout ?? ""}\n${result.stderr ?? ""}\n${logText}`);
-}
-
 export function agentOutputHasExpectedOkMarker(stdout: string, options: AgentOutputOptions = {}) {
   const payloadTexts = parseAgentPayloadTexts(stdout);
   if (payloadTexts.some((text) => text.trim() === "OK")) {

scripts/lib/cross-os-release-checks/installed.ts

@@ -3,7 +3,6 @@ import { appendFileSync, createWriteStream, existsSync, mkdirSync } from "node:f
 import { dirname, join } from "node:path";
 import {
   agentOutputHasExpectedOkMarker,
-  agentTurnUsedEmbeddedFallback,
   buildCrossOsReleaseAgentSessionId,
   buildReleaseAgentTurnArgs,
   maybeBuildOptionalAgentTurnSkipResult,
@@ -766,9 +765,6 @@ export async function runInstalledAgentTurn(params: {
       if (!agentOutputHasExpectedOkMarker(result.stdout, { logText })) {
         throw new Error("Agent output did not contain the expected OK marker.");
       }
-      if (agentTurnUsedEmbeddedFallback(result, { logText })) {
-        throw new Error("Agent turn used embedded fallback instead of gateway.");
-      }
       return result;
     } catch (error) {
       lastError = error;

scripts/lib/cross-os-release-checks/runtime.ts

@@ -2,7 +2,6 @@ import { spawn } from "node:child_process";
 import { appendFileSync, createWriteStream } from "node:fs";
 import {
   agentOutputHasExpectedOkMarker,
-  agentTurnUsedEmbeddedFallback,
   buildCrossOsReleaseAgentSessionId,
   buildReleaseAgentTurnArgs,
   maybeBuildOptionalAgentTurnSkipResult,
@@ -308,9 +307,6 @@ export async function runAgentTurn(
       if (!agentOutputHasExpectedOkMarker(result.stdout, { logText })) {
         throw new Error("Agent output did not contain the expected OK marker.");
       }
-      if (agentTurnUsedEmbeddedFallback(result, { logText })) {
-        throw new Error("Agent turn used embedded fallback instead of gateway.");
-      }
       return result;
     } catch (error) {
       lastError = error;