The API-key connection always presented the key as Authorization:
Bearer. Some providers, notably Anthropic, require the key in a custom
header such as x-api-key and reject Bearer auth, returning 400 when
both headers are present.
Add an optional Header field on APIKeyConnection (empty preserves the
Bearer default for every existing provider) served by a small transport
that omits Authorization, plus a registry-declared APIKeyHeader so the
create-connector resolver wires the right scheme per provider.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>
f6510e25a1