fix: migrate deployment from Hetzner to Coolify (#1)

## Summary
- Add Coolify deployment configuration (docker-compose, healthchecks, network setup)
- Replace deploy-hetzner CI job with Coolify webhook deploy
- Externalize postgres, qdrant, S3 for Coolify environment

## All changes since branch creation
- Coolify docker-compose with Traefik labels and healthchecks
- CI pipeline: deploy-hetzner → deploy-coolify (simple webhook curl)
- SQLAlchemy 2.x text() compatibility fixes
- Alpine-compatible Dockerfile fixes

Co-authored-by: Sharang Parnerkar <parnerkarsharang@gmail.com>
Reviewed-on: #1

developer-portal/Dockerfile

@@ -12,7 +12,7 @@ RUN npm install
 # Copy source code
 COPY . .
 
-# Ensure public directory exists
+# Ensure public directory exists (may not have static assets)
 RUN mkdir -p public
 
 # Build the application
@@ -27,8 +27,8 @@ WORKDIR /app
 ENV NODE_ENV=production
 
 # Create non-root user
-RUN addgroup --system --gid 1001 nodejs
-RUN adduser --system --uid 1001 nextjs
+RUN addgroup -S -g 1001 nodejs
+RUN adduser -S -u 1001 -G nodejs nextjs
 
 # Copy built assets
 COPY --from=builder /app/public ./public