fix: provide prisma datasource fallback

prisma.config.ts

@@ -1,7 +1,53 @@
 import "dotenv/config"
 import path from "node:path"
 
-import { defineConfig, env } from "prisma/config"
+import { defineConfig } from "prisma/config"
+
+const PROJECT_ROOT = process.cwd()
+const PRISMA_DIR = path.join(PROJECT_ROOT, "prisma")
+
+function resolveFileUrl(url: string) {
+  if (!url.startsWith("file:")) {
+    return url
+  }
+
+  const filePath = url.slice("file:".length)
+
+  if (filePath.startsWith("//")) {
+    return url
+  }
+
+  if (path.isAbsolute(filePath)) {
+    return `file:${path.normalize(filePath)}`
+  }
+
+  const normalized = path.normalize(filePath)
+  const prismaPrefix = `prisma${path.sep}`
+  const relativeToPrisma = normalized.startsWith(prismaPrefix)
+    ? normalized.slice(prismaPrefix.length)
+    : normalized
+
+  const absolutePath = path.resolve(PRISMA_DIR, relativeToPrisma)
+
+  if (!absolutePath.startsWith(PROJECT_ROOT)) {
+    throw new Error(`DATABASE_URL path escapes project directory: ${filePath}`)
+  }
+
+  return `file:${absolutePath}`
+}
+
+function normalizeDatasourceUrl(envUrl?: string | null) {
+  const trimmed = envUrl?.trim()
+  if (trimmed) {
+    return resolveFileUrl(trimmed)
+  }
+
+  if (process.env.NODE_ENV === "production") {
+    return "file:/app/data/db.sqlite"
+  }
+
+  return resolveFileUrl("file:./db.dev.sqlite")
+}
 
 export default defineConfig({
   schema: path.join("prisma", "schema.prisma"),
@@ -9,6 +55,6 @@ export default defineConfig({
     path: path.join("prisma", "migrations"),
   },
   datasource: {
-    url: env("DATABASE_URL"),
+    url: normalizeDatasourceUrl(process.env.DATABASE_URL),
   },
 })