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)

turbo.json

@@ -0,0 +1,26 @@
+{
+  "$schema": "https://turbo.build/schema.json",
+  "tasks": {
+    "build": {
+      "inputs": [
+        "src/**",
+        "public/**",
+        "index.html",
+        "*.config.*",
+        "tsconfig*.json",
+        "$VITE_APP_URL",
+        "$VITE_APPWRITE_ENDPOINT",
+        "$VITE_APPWRITE_PROJECT_ID"
+      ],
+      "outputs": ["dist/**"]
+    },
+    "deploy": {
+      "cache": false,
+      "outputs": []
+    },
+    "dev": {
+      "persistent": true,
+      "cache": false
+    }
+  }
+}