[client] Pass stored email as login hint from UI and keep it on logout (#7199)

* [client] Pass stored email as login hint from UI and keep it on logout

Follow the CLI pattern: the Wails UI now reads the account email from the
user-owned profile state file and passes it as the OIDC login_hint on login
and session extend, since the daemon-side fallback runs as root and cannot
see the user's state file. Logout no longer deletes the stored email, so a
later login preselects the account at the IdP; profile removal remains the
operation that deletes it.

* [client] Log ignored profile lookup errors in extend-session hint fallback

client/ui/services/profile.go

@@ -162,8 +162,9 @@ func (s *Profiles) Remove(ctx context.Context, p ProfileRef) error {
 	}
 
 	// The daemon deletes what it owns but runs as root, so it leaves the
-	// user-owned state file holding the account email behind (same split as
-	// Connection.Logout). Legacy profiles are keyed by name rather than by a
+	// user-owned state file holding the account email behind. Logout keeps the
+	// email on purpose so later logins can pass it as the login_hint; profile
+	// removal is what deletes it. Legacy profiles are keyed by name rather than by a
 	// generated ID, so a recreated profile of the same name would inherit the
 	// deleted one's email and offer it as the login_hint.
 	//