refactor: redesign admin permalinks to RESTful paths

- Replace fragile /admin/ai-playground and /admin/ai-generation routes
  with item-scoped /admin/questions/{id}/generate endpoints
- Add /admin/tryouts/{id}/questions route using Tryout primary key
  instead of composite query params (?tryout_id=X&website_id=Y)
- Fix variant detail and review-bulk endpoints to use scoped paths
- Update all internal links (dashboard, hierarchy, exams) to new routes
- Remove obsolete ai_playground_view/submit/save functions

Dockerfile

@@ -0,0 +1,18 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    postgresql-client \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy requirements and install Python dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY . .
+
+# Run migrations and start the app
+CMD ["sh", "-c", "alembic upgrade head && uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload"]