fix(oauth): align zed in OAUTH_PROVIDER_IDS + config enum after #6078 merge

#6078 registered zed in the OAuth PROVIDERS registry but did not add it to the
constants PROVIDERS id map nor the oauth-providers-config enumeration test, leaving
that test red on the release tip (getProvider enumeration vs EXPECTED mismatch).
Adds ZED to the id constants + zed to EXPECTED_PROVIDER_KEYS/EXPECTED_CONFIG_BY_PROVIDER.

src/lib/oauth/constants/oauth.ts

@@ -466,4 +466,5 @@ export const PROVIDERS = {
   TRAE: "trae",
   CODEBUDDY_CN: "codebuddy-cn",
   GROK_CLI: "grok-cli",
+  ZED: "zed",
 };

tests/unit/oauth-providers-config.test.ts

@@ -28,6 +28,7 @@ const {
   CLINE_CONFIG,
   CODEX_CONFIG,
   CODEBUDDY_CN_CONFIG,
+  ZED_CONFIG,
   CURSOR_CONFIG,
   GITHUB_CONFIG,
   GITLAB_DUO_CONFIG,
@@ -66,6 +67,7 @@ const EXPECTED_PROVIDER_KEYS = [
   "devin-cli",
   "grok-cli",
   "codebuddy-cn",
+  "zed",
 ];
 
 const EXPECTED_CONFIG_BY_PROVIDER = {
@@ -88,6 +90,7 @@ const EXPECTED_CONFIG_BY_PROVIDER = {
   trae: TRAE_CONFIG,
   "grok-cli": GROK_CLI_CONFIG,
   "codebuddy-cn": CODEBUDDY_CN_CONFIG,
+  zed: ZED_CONFIG,
 };
 
 const REQUIRED_FIELDS_BY_PROVIDER = {