feat(notifications): requests and flags reach the people who act on them (#5340)

- A new request still pending after any auto-approval notifies the
  admins (request_pending), but not the requester if they are an admin.
  A request that dedups into one already in flight is not announced again.
- Approving or rejecting a request notifies the requester, and a
  rejection carries the admin's notes as the reason. An admin deciding
  their own request gets nothing.
- The reconciler notifies the requester when their request arrives
  (request_completed), linking the matched album or artist.
- A request the re-acquisition sweeper files and cannot approve itself
  notifies the admins.
- A quarantine flag notifies every admin except the flagger, naming the
  track, the flagger and the reason.

lidarrrequests.Service.CreateTracked reports whether a request was
inserted or deduped; Create wraps it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/reacquisition/sweeper.go

@@ -7,12 +7,14 @@ import (
 	"log/slog"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgtype"
 	"github.com/jackc/pgx/v5/pgxpool"
 
 	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/lidarrrequests"
+	"git.fabledsword.com/bvandeusen/minstrel/internal/notifications"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/tags"
 )
 
@@ -20,7 +22,7 @@ import (
 // narrowed to an interface so the pass can be tested without a Lidarr client
 // or an approval path that talks to one.
 type requestCreator interface {
-	Create(ctx context.Context, userID pgtype.UUID, p lidarrrequests.CreateParams) (dbq.LidarrRequest, error)
+	CreateTracked(ctx context.Context, userID pgtype.UUID, p lidarrrequests.CreateParams) (dbq.LidarrRequest, bool, error)
 	Approve(ctx context.Context, requestID, adminID pgtype.UUID, ov lidarrrequests.ApproveOverrides) (dbq.LidarrRequest, error)
 }
 
@@ -37,6 +39,9 @@ type Sweeper struct {
 	settings *SettingsService
 	requests requestCreator
 	logger   *slog.Logger
+	// notifier tells admins about a request the sweeper filed that still
+	// needs their approval (M489). Nil: nobody is told.
+	notifier *notifications.Notifier
 	tick     time.Duration
 	// releaseGroup names the MusicBrainz release group of a release id, for an
 	// album whose tags never carried one (#5241). Lidarr knows albums only by
@@ -92,6 +97,10 @@ type PassResult struct {
 	Unresolved int
 }
 
+// SetNotifier makes requests the sweeper files, and cannot approve itself,
+// reach the admins' notifications inbox (M489).
+func (s *Sweeper) SetNotifier(n *notifications.Notifier) { s.notifier = n }
+
 // SweepOnce runs one pass. Exported so the admin surface can offer a "run
 // now" without waiting out the tick, and so tests drive it directly.
 func (s *Sweeper) SweepOnce(ctx context.Context) error {
@@ -182,7 +191,7 @@ func (s *Sweeper) attempt(
 		return fmt.Errorf("release group: %w", err)
 	}
 
-	req, err := s.requests.Create(ctx, adminID, lidarrrequests.CreateParams{
+	req, created, err := s.requests.CreateTracked(ctx, adminID, lidarrrequests.CreateParams{
 		Kind:             "album",
 		LidarrArtistMBID: *album.ArtistMbid,
 		ArtistName:       album.ArtistName,
@@ -206,11 +215,15 @@ func (s *Sweeper) attempt(
 		return fmt.Errorf("record attempt: %w", err)
 	}
 
+	// A request the sweeper filed and could not approve waits on an admin.
+	// One it deduped into was announced when it was first filed.
+	awaitingAdmin := created
 	if cfg.AutoApprove {
 		_, aerr := s.requests.Approve(ctx, req.ID, adminID, lidarrrequests.ApproveOverrides{})
 		switch {
 		case aerr == nil:
 			res.Approved++
+			awaitingAdmin = false
 		case errors.Is(aerr, lidarrrequests.ErrLidarrDisabled):
 			// Leave it pending rather than treating it as a failure. The
 			// request is still the right record of intent, and it becomes
@@ -225,6 +238,16 @@ func (s *Sweeper) attempt(
 		}
 	}
 
+	if awaitingAdmin {
+		s.notifier.NotifyLogged(ctx, notifications.KindRequestPending, notifications.ToAdmins(pgtype.UUID{}),
+			notifications.Payload{
+				RequestID:   uuid.UUID(req.ID.Bytes).String(),
+				RequestKind: string(req.Kind),
+				Name:        lidarrrequests.DisplayName(req),
+				Actor:       "Re-acquisition",
+			}.Map())
+	}
+
 	if row.Attempts >= cfg.MaxAttempts {
 		if err := q.MarkReacquisitionGaveUp(ctx, album.AlbumID); err != nil {
 			return fmt.Errorf("mark gave up: %w", err)