fix: include anthropic.com cookies in all auth checks and API requests

Claude session cookies are on anthropic.com, not claude.ai. The login
window was not detecting auth (Cancel stayed, no Done) and API calls
were sent without the actual session token.

- claudeCookieHeader: include anthropic.com cookies so the token is
  sent to the usage/bootstrap endpoints
- checkInitialSignInState: detect anthropic.com cookies on startup
- didFinish in LoginView: fire auth when anthropic.com cookies found
- signOut: clear anthropic.com data alongside claude.ai
- notAuthenticated catch: set isSignedIn = false so Settings stays
  in sync with the main panel

ClaudeChecker/LoginView.swift

@@ -38,7 +38,7 @@ struct LoginWebView: NSViewRepresentable {
 
             // URL is not a login/auth page, so if any claude.ai cookie exists we're signed in
             WKWebsiteDataStore.default().httpCookieStore.getAllCookies { cookies in
-                let hasAnyCookie = cookies.contains { $0.domain.contains("claude.ai") }
+                let hasAnyCookie = cookies.contains { $0.domain.contains("claude.ai") || $0.domain.contains("anthropic.com") }
                 guard hasAnyCookie, !self.didAuthenticate else { return }
                 self.didAuthenticate = true
                 DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {