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)

.woodpecker/appwrite.yml

@@ -0,0 +1,58 @@
+# ── Appwrite: Schema Deploy ────────────────────────────────────────────────────
+# Triggered only when files inside apps/appwrite/ change.
+#   main    branch → deploys to production Appwrite project
+#   staging branch → deploys to staging Appwrite project
+#
+# Uses the Appwrite CLI (via apps/appwrite/scripts/deploy.sh) to push the
+# schema defined in apps/appwrite/appwrite.json declaratively.
+#
+# Required Woodpecker secrets:
+#   prod_appwrite_endpoint
+#   prod_appwrite_project_id
+#   prod_appwrite_api_key       needs databases.write + collections.write scopes
+#   staging_appwrite_endpoint
+#   staging_appwrite_project_id
+#   staging_appwrite_api_key
+# ─────────────────────────────────────────────────────────────────────────────
+
+when:
+  - event: push
+    branch:
+      - main
+      - staging
+    path:
+      include:
+        - apps/appwrite/**
+
+steps:
+  - name: deploy-production
+    image: node:20-alpine
+    environment:
+      APPWRITE_ENDPOINT:
+        from_secret: prod_appwrite_endpoint
+      APPWRITE_PROJECT_ID:
+        from_secret: prod_appwrite_project_id
+      APPWRITE_API_KEY:
+        from_secret: prod_appwrite_api_key
+    commands:
+      - npm ci
+      - npm run deploy -w @budgetwise/appwrite
+    when:
+      - branch: main
+        event: push
+
+  - name: deploy-staging
+    image: node:20-alpine
+    environment:
+      APPWRITE_ENDPOINT:
+        from_secret: staging_appwrite_endpoint
+      APPWRITE_PROJECT_ID:
+        from_secret: staging_appwrite_project_id
+      APPWRITE_API_KEY:
+        from_secret: staging_appwrite_api_key
+    commands:
+      - npm ci
+      - npm run deploy -w @budgetwise/appwrite
+    when:
+      - branch: staging
+        event: push