Two honest-feedback fixes in the API-key connect dialog. The
connection-failure toast told managed providers (Crisp) to check their
API key, but Crisp shows no key field; it now points them to the
settings and verification code instead. The verification-code copy
button showed a success toast before the clipboard write resolved; it
now confirms the write and reports a failure with a manual-copy hint,
matching how other copy buttons behave.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>