Add bun integration tests for docs flow, update integration guide

- Add test/integration.test.ts: getServicePublicKey, full flow (register, login, createCollection, createPointFeature, listFeatures)
- Update docs example: registerBySigningServiceKey then loginWithSignature
- Document integration tests in typescript-frontend-integration.md

Made-with: Cursor

internal/store/migrate.go

@@ -0,0 +1,29 @@
+package store
+
+import (
+	"database/sql"
+	"embed"
+	"log"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+//go:embed migrations
+var migrationsFS embed.FS
+
+func Migrate(databaseURL string) error {
+	db, err := sql.Open("pgx", databaseURL)
+	if err != nil {
+		return err
+	}
+	defer db.Close()
+	sql, err := migrationsFS.ReadFile("migrations/0001_init.sql")
+	if err != nil {
+		return err
+	}
+	if _, err := db.Exec(string(sql)); err != nil {
+		return err
+	}
+	log.Printf("migrations applied")
+	return nil
+}