Add public feed, admin area, self-registration, visibility & hashtags

- Public feed (/) with infinite scroll via Intersection Observer
- Self-registration (/register)
- Admin area (/admin/entries, /admin/users) with user management
- journal_entries: visibility (public/private) + hashtags fields
- users: is_admin flag
- DB schema updated (recreate DB to apply)
- CI: run go test via docker run (golang:1.25-alpine) — fixes 'go not found'

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/internal/db/journal.go

@@ -3,6 +3,7 @@ package db
 import (
 	"context"
 
+	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
 
 	"github.com/jacek/pamietnik/backend/internal/domain"
@@ -18,11 +19,17 @@ func NewJournalStore(pool *pgxpool.Pool) *JournalStore {
 
 // InsertEntry creates a new journal entry and returns it with the generated entry_id.
 func (s *JournalStore) InsertEntry(ctx context.Context, e domain.JournalEntry) (domain.JournalEntry, error) {
+	if e.Visibility == "" {
+		e.Visibility = "private"
+	}
+	if e.Hashtags == nil {
+		e.Hashtags = []string{}
+	}
 	err := s.pool.QueryRow(ctx,
-		`INSERT INTO journal_entries (user_id, entry_date, entry_time, title, description, lat, lon)
-		 VALUES ($1, $2, $3, $4, $5, $6, $7)
+		`INSERT INTO journal_entries (user_id, entry_date, entry_time, title, description, lat, lon, visibility, hashtags)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
 		 RETURNING entry_id, created_at`,
-		e.UserID, e.EntryDate, e.EntryTime, e.Title, e.Description, e.Lat, e.Lon,
+		e.UserID, e.EntryDate, e.EntryTime, e.Title, e.Description, e.Lat, e.Lon, e.Visibility, e.Hashtags,
 	).Scan(&e.EntryID, &e.CreatedAt)
 	return e, err
 }
@@ -41,7 +48,7 @@ func (s *JournalStore) InsertImage(ctx context.Context, img domain.JournalImage)
 // ListByDate returns all journal entries for a given date (YYYY-MM-DD), including their images.
 func (s *JournalStore) ListByDate(ctx context.Context, userID, date string) ([]domain.JournalEntry, error) {
 	rows, err := s.pool.Query(ctx,
-		`SELECT entry_id, user_id, entry_date::text, entry_time::text, title, description, lat, lon, created_at
+		`SELECT entry_id, user_id, entry_date::text, entry_time::text, title, description, lat, lon, visibility, hashtags, created_at
 		 FROM journal_entries
 		 WHERE user_id = $1 AND entry_date = $2
 		 ORDER BY entry_time`,
@@ -51,32 +58,78 @@ func (s *JournalStore) ListByDate(ctx context.Context, userID, date string) ([]d
 		return nil, err
 	}
 	defer rows.Close()
+	entries, err := collectEntries(rows)
+	if err != nil {
+		return nil, err
+	}
+	return s.attachImages(ctx, entries)
+}
 
+// ListPublic returns public journal entries ordered by created_at DESC, for infinite scroll.
+func (s *JournalStore) ListPublic(ctx context.Context, limit, offset int) ([]domain.JournalEntry, error) {
+	rows, err := s.pool.Query(ctx,
+		`SELECT entry_id, user_id, entry_date::text, entry_time::text, title, description, lat, lon, visibility, hashtags, created_at
+		 FROM journal_entries
+		 WHERE visibility = 'public'
+		 ORDER BY created_at DESC
+		 LIMIT $1 OFFSET $2`,
+		limit, offset,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	entries, err := collectEntries(rows)
+	if err != nil {
+		return nil, err
+	}
+	return s.attachImages(ctx, entries)
+}
+
+// ListByUser returns all entries for a user, ordered by entry_date DESC, entry_time DESC.
+func (s *JournalStore) ListByUser(ctx context.Context, userID string) ([]domain.JournalEntry, error) {
+	rows, err := s.pool.Query(ctx,
+		`SELECT entry_id, user_id, entry_date::text, entry_time::text, title, description, lat, lon, visibility, hashtags, created_at
+		 FROM journal_entries
+		 WHERE user_id = $1
+		 ORDER BY entry_date DESC, entry_time DESC`,
+		userID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	entries, err := collectEntries(rows)
+	if err != nil {
+		return nil, err
+	}
+	return s.attachImages(ctx, entries)
+}
+
+func collectEntries(rows pgx.Rows) ([]domain.JournalEntry, error) {
 	var entries []domain.JournalEntry
 	for rows.Next() {
 		var e domain.JournalEntry
 		if err := rows.Scan(
 			&e.EntryID, &e.UserID, &e.EntryDate, &e.EntryTime,
-			&e.Title, &e.Description, &e.Lat, &e.Lon, &e.CreatedAt,
+			&e.Title, &e.Description, &e.Lat, &e.Lon, &e.Visibility, &e.Hashtags, &e.CreatedAt,
 		); err != nil {
 			return nil, err
 		}
 		entries = append(entries, e)
 	}
-	if err := rows.Err(); err != nil {
-		return nil, err
-	}
+	return entries, rows.Err()
+}
 
+// attachImages loads images for the given entries in a single query and populates .Images.
+func (s *JournalStore) attachImages(ctx context.Context, entries []domain.JournalEntry) ([]domain.JournalEntry, error) {
 	if len(entries) == 0 {
 		return entries, nil
 	}
-
-	// Load all images in a single query to avoid N+1
 	entryIDs := make([]string, len(entries))
 	for i, e := range entries {
 		entryIDs[i] = e.EntryID
 	}
-
 	imgRows, err := s.pool.Query(ctx,
 		`SELECT image_id, entry_id, filename, original_name, mime_type, size_bytes, created_at
 		 FROM journal_images WHERE entry_id = ANY($1) ORDER BY created_at`,
@@ -101,7 +154,6 @@ func (s *JournalStore) ListByDate(ctx context.Context, userID, date string) ([]d
 	if err := imgRows.Err(); err != nil {
 		return nil, err
 	}
-
 	for i, e := range entries {
 		entries[i].Images = imgMap[e.EntryID]
 	}