fix(sse): retire Microsoft Designer Web runtime (#11720)

Merged via /merge-batch (v3.8.51 provenance sweep). Boarded and validated together with the batch's other retirement PRs in a combined worktree — full gate suite green. This PR's own conflicts (against #11711's EdgeTTS retirement, both touching test-masking-allowlist.json and the "Image / video / audio generation" README bullet) were reconciled additively/subtractively (both retirements now correctly reflected), re-validated with this PR's own 62 focused tests, and pushed before merge. Thank you.

src/shared/constants/designerWebRetirement.ts

@@ -0,0 +1,33 @@
+export const RETIRED_MICROSOFT_DESIGNER_WEB_PROVIDER_IDS: ReadonlySet<string> = new Set([
+  "microsoft-designer-web",
+  "msdesigner",
+]);
+
+export const MICROSOFT_DESIGNER_WEB_RETIRED_MESSAGE =
+  "Provider has been retired from OmniRoute runtime.";
+
+function normalizeProviderId(providerId: unknown): string {
+  return typeof providerId === "string" ? providerId.trim().toLowerCase() : "";
+}
+
+export function isMicrosoftDesignerWebRetiredProviderId(providerId: unknown): boolean {
+  return RETIRED_MICROSOFT_DESIGNER_WEB_PROVIDER_IDS.has(normalizeProviderId(providerId));
+}
+
+export function assertMicrosoftDesignerWebProviderAvailable(providerId: unknown): void {
+  if (!isMicrosoftDesignerWebRetiredProviderId(providerId)) return;
+
+  const error = new Error(MICROSOFT_DESIGNER_WEB_RETIRED_MESSAGE);
+  (error as Error & { status?: number }).status = 410;
+  throw error;
+}
+
+export function isMicrosoftDesignerWebProviderRetiredError(
+  error: unknown
+): error is Error & { status: 410 } {
+  return (
+    error instanceof Error &&
+    (error as Error & { status?: number }).status === 410 &&
+    error.message === MICROSOFT_DESIGNER_WEB_RETIRED_MESSAGE
+  );
+}

src/shared/constants/providers/web-cookie.ts

@@ -156,19 +156,6 @@ export const WEB_COOKIE_PROVIDERS = {
     subscriptionRisk: true,
     riskNoticeVariant: "webCookie",
   },
-  "microsoft-designer-web": {
-    id: "microsoft-designer-web",
-    alias: "msdesigner",
-    name: "Microsoft Designer (Image Generation)",
-    icon: "auto_awesome",
-    color: "#0078D4",
-    textIcon: "MSD",
-    website: "https://designer.microsoft.com",
-    authHint:
-      "Sign in at designer.microsoft.com, then open DevTools → Network, generate an image, and find the request to DallE.ashx?action=GetDallEImagesCogSci. Copy the value of its Authorization: Bearer header (the access_token — no 'Bearer ' prefix). The token is short-lived; this is an unofficial, reverse-engineered integration.",
-    subscriptionRisk: true,
-    riskNoticeVariant: "webCookie",
-  },
   "t3-web": {
     id: "t3-web",
     alias: "t3chat",

src/shared/constants/reservedProviderPrefixes.ts

@@ -11,15 +11,21 @@
 //      provider (tokenrouter bug: "No active credentials for provider:
 //      tokenrouter" despite a fully configured compatible node).
 //
-// Semantics (mirror the original inline runtime guard exactly):
-//   - REGISTRY entry ids + aliases only. Manual alias ids outside REGISTRY
-//     (xiaomi/llamacpp/aq) do NOT intercept nodes at runtime and are therefore
-//     deliberately NOT reserved — including them would cause false-positive
-//     rejections.
-//   - Case-sensitive: mixed-case input like "TokenRouter" does not collide with
-//     the runtime lookup (`Set.has` is exact-match), so it stays allowed.
+// Semantics:
+//   - Live REGISTRY entry ids + aliases, plus exact retired provider ids that
+//     must remain unavailable after their registry entries are removed. Manual
+//     aliases outside REGISTRY (xiaomi/llamacpp/aq) do NOT intercept nodes at
+//     runtime and are therefore deliberately NOT reserved — including them would
+//     cause false-positive rejections.
+//   - Live REGISTRY entries remain case-sensitive. Retired ids use their retirement
+//     normalizer (trim + lowercase), so casing cannot revive a removed provider.
 import { REGISTRY } from "@omniroute/open-sse/config/providerRegistry.ts";
 
+import {
+  isMicrosoftDesignerWebRetiredProviderId,
+  RETIRED_MICROSOFT_DESIGNER_WEB_PROVIDER_IDS,
+} from "@/shared/constants/designerWebRetirement";
+
 let _reserved: Set<string> | null = null;
 
 function buildReservedProviderPrefixes(): Set<string> {
@@ -29,13 +35,16 @@ function buildReservedProviderPrefixes(): Set<string> {
     if (entry?.id) reserved.add(entry.id);
     if (entry?.alias) reserved.add(entry.alias);
   }
+  for (const providerId of RETIRED_MICROSOFT_DESIGNER_WEB_PROVIDER_IDS) {
+    reserved.add(providerId);
+  }
   _reserved = reserved;
   return reserved;
 }
 
 /**
- * All reserved provider prefixes (REGISTRY ids + aliases). Built lazily so the
- * registry is only walked once per process.
+ * All canonical reserved provider prefixes (REGISTRY ids + aliases + retired ids).
+ * Built lazily so the registry is only walked once per process.
  */
 export function getReservedProviderPrefixes(): ReadonlySet<string> {
   return buildReservedProviderPrefixes();
@@ -58,7 +67,10 @@ export const RESERVED_PROVIDER_PREFIXES: ReadonlySet<string> = getReservedProvid
  * reserved (mirrors the runtime guard's typeof check).
  */
 export function isReservedProviderPrefix(value: unknown): boolean {
-  return typeof value === "string" && buildReservedProviderPrefixes().has(value);
+  return (
+    (typeof value === "string" && buildReservedProviderPrefixes().has(value)) ||
+    isMicrosoftDesignerWebRetiredProviderId(value)
+  );
 }
 
 /**

src/shared/providers/webSessionCredentials.ts

@@ -163,13 +163,6 @@ export const WEB_SESSION_CREDENTIAL_REQUIREMENTS = {
     acceptsFullCookieHeader: false,
     storageKeys: ["token", "access_token", "accessToken"],
   },
-  "microsoft-designer-web": {
-    kind: "token",
-    credentialName: "access_token",
-    placeholder: "access_token=... (Authorization: Bearer header from the DallE.ashx request)",
-    acceptsFullCookieHeader: false,
-    storageKeys: ["token", "access_token", "accessToken"],
-  },
   "copilot-m365-web": {
     kind: "token",
     credentialName: "access_token + chathubPath",