Add test steps to Drone CI pipelines before image builds

Frontend pipeline: runs vitest via node:24-alpine before building.
API pipeline: installs deps and runs pytest via python:3.13-slim before building.
Both steps fail-fast (-x) so broken tests block deployment.

.drone.yml

@@ -14,6 +14,13 @@ trigger:
     - push
 
 steps:
+  - name: Run frontend tests
+    image: node:24-alpine
+    commands:
+      - cd frontend
+      - npm ci
+      - npx vitest run
+
   - name: Cache builder stage
     image: plugins/docker
     settings:
@@ -102,6 +109,14 @@ trigger:
     - push
 
 steps:
+  - name: Run backend tests
+    image: python:3.13-slim
+    commands:
+      - apt-get update && apt-get install -y --no-install-recommends gcc libmariadb-dev python3-dev build-essential && rm -rf /var/lib/apt/lists/*
+      - pip install --no-cache-dir -r requirements.txt
+      - pip install --no-cache-dir pytest pytest-asyncio pytest-xdist httpx aioresponses fakeredis
+      - pytest tests/ -x -q
+
   - name: Cache builder stage
     image: plugins/docker
     settings: