feat: Add Pino structured logging, release-please CI/CD and Docker pipeline

Replace all console.log/error with Pino logger (info/warn/error/debug/fatal)
for structured JSON logging in production and pretty-print in development.
Remove redundant header dumps and consolidate rate-limit logging.

Add GitHub Actions workflow with release-please for automated semver releases
and Docker build/push to GHCR on new releases.

server.js

@@ -5,6 +5,7 @@ const { initializeDatabase, checkAndPopulateDatabase } = require('./src/db');
 const playerRoutes = require('./src/routes/players');
 const courseRoutes = require('./src/routes/courses');
 const pageRoutes = require('./src/routes/pages');
+const logger = require('./src/logger');
 
 const app = express();
 const PORT = 3000;
@@ -22,9 +23,9 @@ initializeDatabase().then(async () => {
   await checkAndPopulateDatabase();
 
   app.listen(PORT, () => {
-    console.log(`PDGA Ratings app running on http://localhost:${PORT}`);
+    logger.info(`PDGA Ratings app running on http://localhost:${PORT}`);
   });
 }).catch(err => {
-  console.error('Failed to initialize database:', err);
+  logger.fatal('Failed to initialize database:', err);
   process.exit(1);
 });