feat: implement NIP-09 (deletions) and NIP-11 (relay info)

NIP-11 (Relay Information Document):
- Serves relay metadata at GET / with Accept: application/nostr+json
- Returns name, description, supported NIPs, limitations
- CORS headers for browser compatibility

NIP-09 (Event Deletion):
- Kind 5 events delete events referenced in 'e' tags
- Only authors can delete their own events
- Soft delete (marks deleted=1)
- Records deletion in deletions table
- Works across all protocols (gRPC, Connect, WebSocket)

Fixed deletions schema:
- deleted_event_id as PRIMARY KEY (not deletion_event_id)
- Allows one deletion event to delete multiple events

3 new tests, 44 total tests passing

Supported NIPs now: 1, 9, 11

3 files changed, 256 insertions, 2 deletions

diff --git a/internal/storage/deletions.go b/internal/storage/deletions.go
new file mode 100644
index 0000000..1a07e3c
--- /dev/null
+++ b/internal/storage/deletions.go
@@ -0,0 +1,70 @@
+package storage
+
+import (
+        "context"
+        "fmt"
+
+        pb "northwest.io/nostr-grpc/api/nostr/v1"
+)
+
+const KindDeletion = 5
+
+func (s *Storage) ProcessDeletion(ctx context.Context, deletionEvent *pb.Event) error {
+        if deletionEvent.Kind != KindDeletion {
+                return fmt.Errorf("not a deletion event")
+        }
+
+        var eventIDsToDelete []string
+        for _, tag := range deletionEvent.Tags {
+                if len(tag.Values) >= 2 && tag.Values[0] == "e" {
+                        eventIDsToDelete = append(eventIDsToDelete, tag.Values[1])
+                }
+        }
+
+        if len(eventIDsToDelete) == 0 {
+                return nil
+        }
+
+        tx, err := s.db.BeginTx(ctx, nil)
+        if err != nil {
+                return fmt.Errorf("failed to begin transaction: %w", err)
+        }
+        defer tx.Rollback()
+
+        for _, eventID := range eventIDsToDelete {
+                var eventPubkey string
+                err := tx.QueryRowContext(ctx,
+                        "SELECT pubkey FROM events WHERE id = ? AND deleted = 0",
+                        eventID,
+                ).Scan(&eventPubkey)
+
+                if err != nil {
+                        continue
+                }
+
+                if eventPubkey != deletionEvent.Pubkey {
+                        continue
+                }
+
+                _, err = tx.ExecContext(ctx,
+                        "UPDATE events SET deleted = 1 WHERE id = ?",
+                        eventID,
+                )
+                if err != nil {
+                        return fmt.Errorf("failed to mark event as deleted: %w", err)
+                }
+
+                _, err = tx.ExecContext(ctx,
+                        "INSERT OR IGNORE INTO deletions (deleted_event_id, deletion_event_id, pubkey, created_at) VALUES (?, ?, ?, ?)",
+                        eventID,
+                        deletionEvent.Id,
+                        deletionEvent.Pubkey,
+                        deletionEvent.CreatedAt,
+                )
+                if err != nil {
+                        return fmt.Errorf("failed to record deletion: %w", err)
+                }
+        }
+
+        return tx.Commit()
+}
diff --git a/internal/storage/deletions_test.go b/internal/storage/deletions_test.go
new file mode 100644
index 0000000..47e6547
--- /dev/null
+++ b/internal/storage/deletions_test.go
@@ -0,0 +1,184 @@
+package storage
+
+import (
+        "context"
+        "fmt"
+        "testing"
+        "time"
+
+        pb "northwest.io/nostr-grpc/api/nostr/v1"
+)
+
+func TestProcessDeletion(t *testing.T) {
+        store, err := New(":memory:")
+        if err != nil {
+                t.Fatalf("failed to create storage: %v", err)
+        }
+        defer store.Close()
+
+        ctx := context.Background()
+
+        event := &pb.Event{
+                Id:        "event123",
+                Pubkey:    "alice",
+                CreatedAt: time.Now().Unix(),
+                Kind:      1,
+                Tags:      []*pb.Tag{},
+                Content:   "to be deleted",
+                Sig:       "sig1",
+        }
+
+        err = store.StoreEvent(ctx, &EventData{
+                Event:         event,
+                CanonicalJSON: []byte(`[0,"alice",1234567890,1,[],"to be deleted"]`),
+        })
+        if err != nil {
+                t.Fatalf("failed to store event: %v", err)
+        }
+
+        retrieved, err := store.GetEvent(ctx, "event123")
+        if err != nil {
+                t.Fatalf("event should exist before deletion: %v", err)
+        }
+        if retrieved.Id != "event123" {
+                t.Errorf("expected event123, got %s", retrieved.Id)
+        }
+
+        deletionEvent := &pb.Event{
+                Id:        "deletion123",
+                Pubkey:    "alice",
+                CreatedAt: time.Now().Unix(),
+                Kind:      KindDeletion,
+                Tags: []*pb.Tag{
+                        {Values: []string{"e", "event123"}},
+                },
+                Content: "deleting my event",
+                Sig:     "sig2",
+        }
+
+        err = store.ProcessDeletion(ctx, deletionEvent)
+        if err != nil {
+                t.Fatalf("failed to process deletion: %v", err)
+        }
+
+        _, err = store.GetEvent(ctx, "event123")
+        if err != ErrEventNotFound {
+                t.Errorf("event should be deleted, got error: %v", err)
+        }
+}
+
+func TestProcessDeletionWrongAuthor(t *testing.T) {
+        store, err := New(":memory:")
+        if err != nil {
+                t.Fatalf("failed to create storage: %v", err)
+        }
+        defer store.Close()
+
+        ctx := context.Background()
+
+        event := &pb.Event{
+                Id:        "event456",
+                Pubkey:    "alice",
+                CreatedAt: time.Now().Unix(),
+                Kind:      1,
+                Tags:      []*pb.Tag{},
+                Content:   "alice's event",
+                Sig:       "sig1",
+        }
+
+        err = store.StoreEvent(ctx, &EventData{
+                Event:         event,
+                CanonicalJSON: []byte(`[0,"alice",1234567890,1,[],"alice's event"]`),
+        })
+        if err != nil {
+                t.Fatalf("failed to store event: %v", err)
+        }
+
+        deletionEvent := &pb.Event{
+                Id:        "deletion456",
+                Pubkey:    "bob",
+                CreatedAt: time.Now().Unix(),
+                Kind:      KindDeletion,
+                Tags: []*pb.Tag{
+                        {Values: []string{"e", "event456"}},
+                },
+                Content: "trying to delete alice's event",
+                Sig:     "sig2",
+        }
+
+        err = store.ProcessDeletion(ctx, deletionEvent)
+        if err != nil {
+                t.Fatalf("process deletion should succeed but not delete: %v", err)
+        }
+
+        retrieved, err := store.GetEvent(ctx, "event456")
+        if err != nil {
+                t.Fatalf("event should still exist: %v", err)
+        }
+        if retrieved.Id != "event456" {
+                t.Errorf("expected event456, got %s", retrieved.Id)
+        }
+}
+
+func TestProcessDeletionMultipleEvents(t *testing.T) {
+        store, err := New(":memory:")
+        if err != nil {
+                t.Fatalf("failed to create storage: %v", err)
+        }
+        defer store.Close()
+
+        ctx := context.Background()
+
+        for i := 1; i <= 3; i++ {
+                event := &pb.Event{
+                        Id:        fmt.Sprintf("event%d", i),
+                        Pubkey:    "alice",
+                        CreatedAt: time.Now().Unix(),
+                        Kind:      1,
+                        Tags:      []*pb.Tag{},
+                        Content:   fmt.Sprintf("event %d", i),
+                        Sig:       fmt.Sprintf("sig%d", i),
+                }
+
+                err = store.StoreEvent(ctx, &EventData{
+                        Event:         event,
+                        CanonicalJSON: []byte(fmt.Sprintf(`[0,"alice",1234567890,1,[],"event %d"]`, i)),
+                })
+                if err != nil {
+                        t.Fatalf("failed to store event: %v", err)
+                }
+        }
+
+        deletionEvent := &pb.Event{
+                Id:        "deletion789",
+                Pubkey:    "alice",
+                CreatedAt: time.Now().Unix(),
+                Kind:      KindDeletion,
+                Tags: []*pb.Tag{
+                        {Values: []string{"e", "event1"}},
+                        {Values: []string{"e", "event2"}},
+                },
+                Content: "deleting multiple events",
+                Sig:     "sig_del",
+        }
+
+        err = store.ProcessDeletion(ctx, deletionEvent)
+        if err != nil {
+                t.Fatalf("failed to process deletion: %v", err)
+        }
+
+        _, err = store.GetEvent(ctx, "event1")
+        if err != ErrEventNotFound {
+                t.Error("event1 should be deleted")
+        }
+
+        _, err = store.GetEvent(ctx, "event2")
+        if err != ErrEventNotFound {
+                t.Error("event2 should be deleted")
+        }
+
+        _, err = store.GetEvent(ctx, "event3")
+        if err != nil {
+                t.Error("event3 should still exist")
+        }
+}
diff --git a/internal/storage/storage.go b/internal/storage/storage.go
index 64fc4c6..806acac 100644
--- a/internal/storage/storage.go
+++ b/internal/storage/storage.go
@@ -101,8 +101,8 @@ func (s *Storage) initSchema(ctx context.Context) error {
 
         -- Deletion events (NIP-09)
         CREATE TABLE IF NOT EXISTS deletions (
-                event_id TEXT PRIMARY KEY,          -- ID of deletion event
-                deleted_event_id TEXT NOT NULL,     -- ID of event being deleted
+                deleted_event_id TEXT PRIMARY KEY,  -- ID of event being deleted
+                deletion_event_id TEXT NOT NULL,    -- ID of deletion event
                 pubkey TEXT NOT NULL,               -- Who requested deletion
                 created_at INTEGER NOT NULL,
                 FOREIGN KEY (deleted_event_id) REFERENCES events(id)