feat(store): add read methods for stored summaries

ListSummaries (recent-first, user-scoped, limit) and GetSummaryByVideo
LEFT JOIN videos for title/url/published_at, null-safe when no videos
row exists. Channel mirrors provider for now — channel_title lives on
the not-yet-migrated subscriptions table (data-model.md). New file so it
does not collide with Worker F's concurrent edits to store.go.

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

internal/adapters/store/reads_test.go

@@ -0,0 +1,148 @@
+package store_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/stretchr/testify/require"
+
+	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
+)
+
+// seedVideo inserts a videos row whose id matches a summary's video_id, so the
+// read-side LEFT JOIN has metadata to attach. published_at may be the zero time
+// to exercise the NULL path.
+func seedVideo(t *testing.T, p *pgxpool.Pool, userID, videoID, title, provider, url string, published time.Time) {
+	t.Helper()
+	var pub any
+	if !published.IsZero() {
+		pub = published
+	}
+	_, err := p.Exec(context.Background(),
+		`INSERT INTO videos (id, user_id, provider, provider_video_id, title, url, published_at)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7)`,
+		videoID, userID, provider, "pv-"+videoID[:8], title, url, pub)
+	require.NoError(t, err)
+}
+
+// setCreatedAt forces a summary's created_at so ordering is deterministic.
+func setCreatedAt(t *testing.T, p *pgxpool.Pool, userID, videoID string, at time.Time) {
+	t.Helper()
+	_, err := p.Exec(context.Background(),
+		`UPDATE summaries SET created_at = $3 WHERE user_id = $1 AND video_id = $2`,
+		userID, videoID, at)
+	require.NoError(t, err)
+}
+
+func TestListSummariesRecentFirstWithVideoMetadata(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	p := rawPool(t)
+	resetDB(t, p)
+
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "older")))
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoY, "newer")))
+	seedVideo(t, p, userA, videoX, "X Title", "youtube", "https://x", time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC))
+	seedVideo(t, p, userA, videoY, "Y Title", "youtube", "https://y", time.Date(2026, 2, 1, 0, 0, 0, 0, time.UTC))
+	// Force ordering: videoY is the most recent.
+	setCreatedAt(t, p, userA, videoX, time.Date(2026, 3, 1, 0, 0, 0, 0, time.UTC))
+	setCreatedAt(t, p, userA, videoY, time.Date(2026, 3, 2, 0, 0, 0, 0, time.UTC))
+
+	rows, err := s.ListSummaries(ctx, userA, 50)
+	require.NoError(t, err)
+	require.Len(t, rows, 2)
+
+	require.Equal(t, videoY, rows[0].VideoID, "most recent created_at first")
+	require.Equal(t, "Y Title", rows[0].Title)
+	require.Equal(t, "youtube", rows[0].Channel)
+	require.Equal(t, "https://y", rows[0].URL)
+	require.Equal(t, 2026, rows[0].PublishedAt.Year())
+
+	require.Equal(t, videoX, rows[1].VideoID)
+	require.Equal(t, "X Title", rows[1].Title)
+}
+
+func TestListSummariesWithoutVideoRowIsNullSafe(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	// Summary exists but no matching videos row (run loop hasn't populated it).
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "orphan")))
+
+	rows, err := s.ListSummaries(ctx, userA, 50)
+	require.NoError(t, err)
+	require.Len(t, rows, 1)
+	require.Empty(t, rows[0].Title, "no videos row -> empty title (caller falls back to id)")
+	require.Empty(t, rows[0].Channel)
+	require.Empty(t, rows[0].URL)
+	require.True(t, rows[0].PublishedAt.IsZero(), "absent published_at -> zero time")
+	require.Equal(t, "orphan", rows[0].Summary)
+}
+
+func TestListSummariesRespectsLimit(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	p := rawPool(t)
+	resetDB(t, p)
+
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "x")))
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoY, "y")))
+	setCreatedAt(t, p, userA, videoX, time.Date(2026, 3, 1, 0, 0, 0, 0, time.UTC))
+	setCreatedAt(t, p, userA, videoY, time.Date(2026, 3, 2, 0, 0, 0, 0, time.UTC))
+
+	rows, err := s.ListSummaries(ctx, userA, 1)
+	require.NoError(t, err)
+	require.Len(t, rows, 1)
+	require.Equal(t, videoY, rows[0].VideoID, "limit keeps the most recent")
+}
+
+func TestListSummariesIsUserScoped(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "a-only")))
+
+	rows, err := s.ListSummaries(ctx, userB, 50)
+	require.NoError(t, err)
+	require.Empty(t, rows, "user B must not see user A's summaries")
+}
+
+func TestGetSummaryByVideoReturnsFullRow(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "full body")))
+
+	row, err := s.GetSummaryByVideo(ctx, userA, videoX)
+	require.NoError(t, err)
+	require.Equal(t, "full body", row.Summary)
+	require.Equal(t, []string{"h1", "h2"}, row.Highlights)
+	require.Equal(t, []string{"t1"}, row.Takeaways)
+	require.Equal(t, "local", row.AIProvider)
+	require.Equal(t, "qwen", row.AIModel)
+}
+
+func TestGetSummaryByVideoNotFound(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	_, err := s.GetSummaryByVideo(ctx, userA, videoX)
+	require.ErrorIs(t, err, store.ErrNotFound)
+}
+
+func TestGetSummaryByVideoIsUserScoped(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	require.NoError(t, s.Deliver(ctx, summary(userA, videoX, "a-owns")))
+
+	_, err := s.GetSummaryByVideo(ctx, userB, videoX)
+	require.ErrorIs(t, err, store.ErrNotFound, "the same video under another user is invisible")
+}