fix: use bun:sqlite in production, better-sqlite3 as test-only devDep

Production (Docker): src/lib/db.ts now uses bun:sqlite + drizzle-orm/bun-sqlite.
No native addon compilation needed — bun:sqlite is a Bun built-in. The Dockerfile
drops all native build tools (python3, make, g++) and uses --ignore-scripts.

Tests (Vitest/Node.js): bun:sqlite is unavailable under Node.js, so:
- tests/helpers/db.ts keeps better-sqlite3 + drizzle-orm/better-sqlite3 for
  integration tests that need a real in-memory SQLite
- vitest.config.ts aliases bun:sqlite → a thin better-sqlite3 shim and
  drizzle-orm/bun-sqlite → drizzle-orm/better-sqlite3 for unit tests that
  transitively import src/lib/db.ts without executing any queries
- better-sqlite3 stays as a devDependency (test-only, not built in Docker)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bun.lock

@@ -10,10 +10,8 @@
         "@mui/icons-material": "^7.3.9",
         "@mui/material": "^7.3.9",
         "@mui/x-date-pickers": "^8.27.2",
-        "@types/better-sqlite3": "^7.6.13",
         "apexcharts": "^5.10.4",
         "bcryptjs": "^3.0.3",
-        "better-sqlite3": "^12.8.0",
         "d3-geo": "^3.1.1",
         "dayjs": "^1.11.20",
         "drizzle-orm": "^0.45.1",
@@ -32,6 +30,7 @@
         "@eslint/js": "^10.0.1",
         "@next/eslint-plugin-next": "^16.1.7",
         "@playwright/test": "^1.58.2",
+        "@types/better-sqlite3": "^7.6.13",
         "@types/bun": "latest",
         "@types/d3-geo": "^3.1.0",
         "@types/node": "^25.5.0",
@@ -40,6 +39,7 @@
         "@types/react-dom": "^19.2.3",
         "@types/topojson-client": "^3.1.5",
         "@vitest/ui": "^4.1.0",
+        "better-sqlite3": "^12.8.0",
         "drizzle-kit": "^0.31.10",
         "eslint": "^10.0.3",
         "typescript": "^5.9.3",