feat(phase-15): add Test Catalog page, template instantiation, and auto-migration entrypoint (T-119, T-120, T-121)

T-119: TestCatalogPage with search, filters (source/platform/severity), template cards grid, and pagination

T-120: TestFromTemplateForm modal with pre-filled fields from template, required field validation, and redirect on creation

T-121: Integrate Available Test Templates section in TechniqueDetailPage with Run This Test buttons; fix missing testStateBadgeColors for new states

Also: add backend entrypoint.sh for automatic Alembic migrations + seed on container startup, add curl to Dockerfile for healthcheck

backend/Dockerfile

@@ -6,6 +6,7 @@ WORKDIR /app
 RUN apt-get update && apt-get install -y \
     gcc \
     libpq-dev \
+    curl \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy requirements first for better caching
@@ -15,8 +16,11 @@ RUN pip install --no-cache-dir -r requirements.txt
 # Copy application code
 COPY . .
 
+# Make entrypoint executable
+RUN chmod +x /app/entrypoint.sh
+
 # Expose port
 EXPOSE 8000
 
-# Default command
-CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]
+# Default command (migrations + seed + uvicorn)
+CMD ["sh", "/app/entrypoint.sh"]