fix(store): scope SetDomainStatus by project (IDOR); scheduler reuses DeriveStatus

handleCheck's error branch wrote last_check_status via an id-only UPDATE, so
an authenticated caller's own valid project id paired with a foreign domain
id in the URL could flip a stranger's domain to "error" even though Check
itself is project-scoped and would 404/error out first. Add project_id to
the WHERE clause (queries/domains.sql + generated db/domains.sql.go), thread
projectID through Store/TenantStore/SchedStore SetDomainStatus, and pass pid
from context at both call sites in handleCheck plus the scheduler.

Also collapse checkDomain's inline status derivation in scheduler.go into a
call to service.DeriveStatus, the same helper handleCheck already uses, so
there's a single source of truth for "drift vs in_sync" instead of two
copies that could drift apart.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwxdSt4reTm7Dj1oxRvpP3

internal/api/api.go

@@ -52,8 +52,9 @@ type TenantStore interface {
 	SetDomainTemplate(ctx context.Context, domainID, projectID uuid.UUID, templateID *uuid.UUID) (store.Domain, error)
 	// SetDomainStatus persists the outcome of a manual check (handleCheck) so
 	// the domain's badge reflects reality immediately, instead of staying
-	// "unknown" until the scheduler's next tick.
-	SetDomainStatus(ctx context.Context, domainID uuid.UUID, status string) error
+	// "unknown" until the scheduler's next tick. Scoped by projectID so a
+	// foreign domain ID can never have its status overwritten (IDOR-on-write).
+	SetDomainStatus(ctx context.Context, domainID, projectID uuid.UUID, status string) error
 }
 
 // Cipher encrypts/decrypts provider account secrets. *crypto.Cipher satisfies it.