Add event image upload endpoint and refactor image upload handling

- Introduced `/events/upload` endpoint for securely uploading and processing event images.
- Added image validation, resizing, and conversion to WebP with fallback support for original formats.
- Updated `uploadImage` to `uploadEventImage` and introduced `uploadGalleryImage` in `admin.astro`.

backend/src/routes/events.ts

@@ -2,6 +2,9 @@ import { FastifyPluginAsync } from 'fastify';
 import { db } from '../config/database.js';
 import { events } from '../db/schema.js';
 import { eq } from 'drizzle-orm';
+import fs from 'fs';
+import path from 'path';
+import sharp from 'sharp';
 
 // Fastify JSON schema for event body
 const eventBodyJsonSchema = {
@@ -74,6 +77,70 @@ const eventsRoute: FastifyPluginAsync = async (fastify) => {
     return { event: row };
   });
 
+  // Upload event image file (multipart)
+  fastify.post('/events/upload', {
+    preHandler: [fastify.authenticate],
+  }, async (request, reply) => {
+    try {
+      // Expect a single file field named "file"
+      const file = await (request as any).file();
+      if (!file) {
+        return reply.code(400).send({ error: 'No file uploaded' });
+      }
+
+      const mime = file.mimetype as string | undefined;
+      if (!mime || !mime.startsWith('image/')) {
+        return reply.code(400).send({ error: 'Only image uploads are allowed' });
+      }
+
+      // Prepare directories - use persistent volume for Fly.io
+      const dataDir = process.env.GIT_WORKSPACE_DIR || path.join(process.cwd(), 'data');
+      const uploadDir = path.join(dataDir, 'images', 'events');
+      if (!fs.existsSync(uploadDir)) fs.mkdirSync(uploadDir, { recursive: true });
+
+      // Read uploaded stream into buffer
+      const chunks: Buffer[] = [];
+      for await (const chunk of file.file) {
+        chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
+      }
+      const inputBuffer = Buffer.concat(chunks);
+
+      // Generate filename
+      const stamp = Date.now().toString(36);
+      const rand = Math.random().toString(36).slice(2, 8);
+      const baseName = `${stamp}-${rand}`;
+
+      // Try to convert to webp and limit size; fallback to original
+      let outBuffer: Buffer | null = null;
+      let outExt = '.webp';
+      try {
+        outBuffer = await sharp(inputBuffer)
+          .rotate()
+          .resize({ width: 1600, withoutEnlargement: true })
+          .webp({ quality: 82 })
+          .toBuffer();
+      } catch {
+        outBuffer = inputBuffer;
+        // naive extension from mimetype
+        const extFromMime = mime.split('/')[1] || 'bin';
+        outExt = '.' + extFromMime.replace(/[^a-z0-9]/gi, '').toLowerCase();
+      }
+
+      const filename = baseName + outExt;
+      const destPath = path.join(uploadDir, filename);
+      fs.writeFileSync(destPath, outBuffer);
+
+      // Public URL (served via /static)
+      const publicUrl = `/static/images/events/${filename}`;
+
+      return reply.code(201).send({ imageUrl: publicUrl });
+
+    } catch (err) {
+      fastify.log.error({ err }, 'Upload failed');
+      return reply.code(500).send({ error: 'Failed to upload image' });
+    }
+  });
+
   // Delete event
   fastify.delete('/events/:id', { preHandler: [fastify.authenticate] }, async (request, reply) => {
     const { id } = request.params as { id: string };