Convert backend from submodule to regular directory

Remove submodule tracking; backend is now a plain directory in the repo.
Also update deploy workflow: remove --recurse-submodules.

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

backend/cmd/createuser/main.go

@@ -0,0 +1,55 @@
+// cmd/createuser creates a new user in the database.
+// Usage: DATABASE_URL=... go run ./cmd/createuser <username> <password>
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/jackc/pgx/v5"
+
+	"github.com/jacek/pamietnik/backend/internal/auth"
+)
+
+func main() {
+	if len(os.Args) != 3 {
+		fmt.Fprintln(os.Stderr, "usage: createuser <username> <password>")
+		os.Exit(1)
+	}
+	username := os.Args[1]
+	password := os.Args[2]
+
+	if len(password) < 8 {
+		fmt.Fprintln(os.Stderr, "password must be at least 8 characters")
+		os.Exit(1)
+	}
+
+	dsn := os.Getenv("DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://pamietnik:pamietnik@localhost:5432/pamietnik?sslmode=disable"
+	}
+
+	conn, err := pgx.Connect(context.Background(), dsn)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "db error:", err)
+		os.Exit(1)
+	}
+	defer conn.Close(context.Background())
+
+	hash, err := auth.HashPassword(password)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "hash error:", err)
+		os.Exit(1)
+	}
+
+	_, err = conn.Exec(context.Background(),
+		`INSERT INTO users (username, password_hash) VALUES ($1, $2)`,
+		username, hash,
+	)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "insert error:", err)
+		os.Exit(1)
+	}
+	fmt.Printf("user '%s' created\n", username)
+}

backend/cmd/server/main.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/jacek/pamietnik/backend/internal/api"
+	"github.com/jacek/pamietnik/backend/internal/auth"
+	"github.com/jacek/pamietnik/backend/internal/db"
+)
+
+func main() {
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
+	slog.SetDefault(logger)
+
+	dsn := getenv("DATABASE_URL", "postgres://pamietnik:pamietnik@localhost:5432/pamietnik?sslmode=disable")
+	addr := getenv("LISTEN_ADDR", ":8080")
+	uploadDir := getenv("UPLOAD_DIR", "./uploads")
+
+	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer cancel()
+
+	pool, err := db.NewPool(ctx, dsn)
+	if err != nil {
+		slog.Error("connect db", "err", err)
+		os.Exit(1)
+	}
+	defer pool.Close()
+	slog.Info("database connected")
+
+	if err := db.InitSchema(ctx, pool); err != nil {
+		slog.Error("init schema", "err", err)
+		os.Exit(1)
+	}
+	slog.Info("schema ready")
+
+	if err := os.MkdirAll(uploadDir, 0o755); err != nil {
+		slog.Error("create upload dir", "err", err)
+		os.Exit(1)
+	}
+
+	authStore := auth.NewStore(pool)
+	tpStore := db.NewTrackpointStore(pool)
+	stopStore := db.NewStopStore(pool)
+	suggStore := db.NewSuggestionStore(pool)
+	journalStore := db.NewJournalStore(pool)
+
+	router := api.NewRouter(authStore, tpStore, stopStore, suggStore, journalStore, uploadDir)
+
+	srv := &http.Server{
+		Addr:         addr,
+		Handler:      router,
+		ReadTimeout:  15 * time.Second,
+		WriteTimeout: 30 * time.Second,
+		IdleTimeout:  60 * time.Second,
+	}
+
+	go func() {
+		slog.Info("server starting", "addr", addr)
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			slog.Error("server error", "err", err)
+			cancel()
+		}
+	}()
+
+	<-ctx.Done()
+	slog.Info("shutting down")
+
+	shutCtx, shutCancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer shutCancel()
+	if err := srv.Shutdown(shutCtx); err != nil {
+		slog.Error("shutdown error", "err", err)
+	}
+	slog.Info("server stopped")
+}
+
+func getenv(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}