chore: convert to Turborepo + npm workspaces monorepo

- Move React/Vite frontend to apps/web/ (@budgetwise/web)
- Add apps/appwrite/ (@budgetwise/appwrite) to source-control the
  Appwrite backend: declarative schema in appwrite.json (5 collections),
  CLI-based deploy.sh for containerized use, functions/ dir for future
  Appwrite Functions
- Add turbo.json for task orchestration (build, deploy, dev)
- Replace .gitlab-ci.yml with Woodpecker CI pipelines in .woodpecker/:
    web-production.yml  — push to main → build + rsync to prod
    web-staging.yml     — push to staging → build + rsync to staging
    web-preview.yml     — PR open → deploy to {pr}.{domain}; PR close → cleanup
    appwrite.yml        — schema changes in apps/appwrite/ → CLI deploy
- All secrets injected via Woodpecker CI (no committed .env files)

apps/appwrite/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "@budgetwise/appwrite",
+  "private": true,
+  "version": "1.0.0",
+  "scripts": {
+    "deploy": "bash scripts/deploy.sh",
+    "setup": "node scripts/setup-appwrite.cjs"
+  },
+  "devDependencies": {
+    "node-appwrite": "^12.0.0"
+  }
+}