fix(scheduler): skip discovery for users with no video connection

The scheduler enumerates every user_identities row (ListAllUsers) and ran a
discovery pass for each — including users who never connected a video source.
Their per-user runner then tried to resolve a YouTube refresh token that was
never minted, logging a spurious "secrets: ref not found:
youtube/<uid>/refresh_token" every tick (e.g. stale Dex-era orphan identities
left by the Authentik migration).

Skip users whose ConnectionsForUser is empty before running their pass. Removes
the recurring noise — which actively misled a debug session into thinking a
healthy onboarded user was broken — with no change to connected users.

Refs #7

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cmd/tapir/scheduler.go

@@ -49,10 +49,12 @@ func buildUserRunner(cfg config.Config, st *store.Store, secretStore ports.Secre
 		runner.WithAutoWindow(cfg.AutoSummarizeWindow)), nil
 }
 
-// userLister enumerates every registered user. *store.Store satisfies it via
-// ListAllUsers. A small local interface keeps the scheduler testable with a fake.
+// userLister enumerates every registered user and reports a user's video
+// connections. *store.Store satisfies it via ListAllUsers + ConnectionsForUser.
+// A small local interface keeps the scheduler testable with a fake.
 type userLister interface {
 	ListAllUsers(ctx context.Context) ([]store.UserIdentity, error)
+	ConnectionsForUser(ctx context.Context, userID string) ([]store.Connection, error)
 }
 
 // runDiscoveryPass runs one discovery pass for every user. runUser performs a
@@ -78,6 +80,18 @@ func runDiscoveryPass(
 		if ctx.Err() != nil {
 			break // shutting down: stop enumerating
 		}
+		// Skip users with no video connection. A discovery pass for them only
+		// attempts to resolve a token that was never minted, logging a spurious
+		// "ref not found" every tick (e.g. stale Dex-era orphan identities).
+		conns, err := lister.ConnectionsForUser(ctx, u.UserID)
+		if err != nil {
+			log.Warn("scheduler: list connections failed", "user", u.UserID, "err", err)
+			continue
+		}
+		if len(conns) == 0 {
+			log.Debug("scheduler: skipping user with no video connections", "user", u.UserID)
+			continue
+		}
 		stats, err := runUser(ctx, u.UserID)
 		total = sumStats(total, stats)
 		if err != nil {