fix(zed): harden OAuth lifecycle and live model support

- executors/zed.js: use exact wire values (anthropic, open_ai, google, x_ai)
  and strip incompatible Vertex safetySettings on the Google path
- shared/zedAuth.js: robust callback query parsing, reject garbage PKCS#1 v1.5
  decryptions, and thread proxyOptions when fetching LLM tokens
- oauth: preserve systemId across authorize/register/exchange lifecycle,
  renew proxy idle timeout on reuse, and ignore non-callback localhost requests
- shared/OAuthModal.js: track owned proxy in flowRef and stop at most once
- api/providers/[id]/models: add connection-scoped live Zed model resolver
- registry: unhide provider in dashboard
- tests: add unit coverage for wire format, native auth, and live models

open-sse/shared/zedAuth.js

@@ -112,7 +112,14 @@ export function parseZedCallbackPayload(input) {
       url = new URL(raw);
     } catch {
       try {
-        url = new URL(`http://127.0.0.1/?${raw.replace(/^\?/, "")}`);
+        // Accept pathname+query (what the local proxy forwards, e.g.
+        // "/?user_id=..&access_token=.." or "/callback?.."), a bare query,
+        // or a lone query string. Only the query part is parsed — a leading
+        // path must never become part of the first parameter name.
+        const query = raw.includes("?")
+          ? raw.slice(raw.indexOf("?") + 1)
+          : raw.replace(/^\?/, "");
+        url = new URL(`http://127.0.0.1/?${query}`);
       } catch {
         throw new Error("Invalid Zed callback URL");
       }
@@ -134,6 +141,10 @@ export function parseZedCallbackPayload(input) {
 export function decryptZedAccessToken(encryptedAccessToken, privateKeyVerifier) {
   const privateKey = decodeZedPrivateKeyVerifier(privateKeyVerifier);
   const encrypted = Buffer.from(String(encryptedAccessToken), "base64url");
+  const fail = (oaepError) => {
+    const message = oaepError instanceof Error ? oaepError.message : String(oaepError);
+    throw new Error(`Failed to decrypt Zed access token: ${message}`);
+  };
   try {
     return crypto
       .privateDecrypt(
@@ -143,15 +154,21 @@ export function decryptZedAccessToken(encryptedAccessToken, privateKeyVerifier)
       .toString("utf8");
   } catch (oaepError) {
     try {
-      return crypto
+      const text = crypto
         .privateDecrypt(
           { key: privateKey, padding: crypto.constants.RSA_PKCS1_PADDING },
           encrypted,
         )
         .toString("utf8");
-    } catch {
-      const message = oaepError instanceof Error ? oaepError.message : String(oaepError);
-      throw new Error(`Failed to decrypt Zed access token: ${message}`);
+      // PKCS#1 v1.5 unpadding is not integrity-checked: a wrong-key decrypt
+      // can "succeed" with garbage bytes instead of throwing. Replacement
+      // characters prove the output is not the real UTF-8 token — fail loudly
+      // rather than storing garbage as a credential.
+      if (text.includes("<22>")) fail(oaepError);
+      return text;
+    } catch (err) {
+      if (err.message.startsWith("Failed to decrypt Zed access token")) throw err;
+      fail(oaepError);
     }
   }
 }
@@ -280,6 +297,7 @@ export async function fetchZedLlmToken(credentials, options = {}) {
       body: JSON.stringify({ organization_id: organizationId }),
       signal: options.signal ?? undefined,
     },
+    options.proxyOptions ?? null,
   );
   const token =
     typeof data?.token === "string" ? data.token : data?.token?.[0] || data?.token?.value;