fix(auth): align profile-id in config with writeOAuthCredentials

writeOAuthCredentials writes profile as `provider:email` when email is
present, but applyAuthProfileConfig was always called with `provider:default`.
This caused config to reference a non-existent profile when OAuth returned
an email.

Compute the same profile-id (email or 'default' fallback) in both
auth-choice.apply.oauth.ts (chutes) and auth-choice.apply.openai.ts
(openai-codex) so config references the actually-written profile.

Fixes failing tests:
- stores openai-codex OAuth with email profile id
- writes Chutes OAuth credentials when selecting chutes (remote/manual)

src/commands/auth-choice.apply.oauth.ts

@@ -69,8 +69,10 @@ export async function applyAuthChoiceOAuth(
 
       spin.stop("Chutes OAuth complete");
       await writeOAuthCredentials("chutes", creds, params.agentDir);
+      const chutesEmail =
+        typeof creds.email === "string" && creds.email.trim() ? creds.email.trim() : "default";
       nextConfig = applyAuthProfileConfig(nextConfig, {
-        profileId: "chutes:default",
+        profileId: `chutes:${chutesEmail}`,
         provider: "chutes",
         mode: "oauth",
       });

src/commands/auth-choice.apply.openai.ts

@@ -120,8 +120,10 @@ export async function applyAuthChoiceOpenAI(
       await writeOAuthCredentials("openai-codex", creds, params.agentDir, {
         syncSiblingAgents: true,
       });
+      const codexEmail =
+        typeof creds.email === "string" && creds.email.trim() ? creds.email.trim() : "default";
       nextConfig = applyAuthProfileConfig(nextConfig, {
-        profileId: "openai-codex:default",
+        profileId: `openai-codex:${codexEmail}`,
         provider: "openai-codex",
         mode: "oauth",
       });