fix: resolve Elysia framework and Vite URI error bugs

- Fix onResponse error by using onAfterHandle for Elysia framework
- Fix URI malformed errors from browser extensions in Vite dev server
- Update middleware plugin to run before SvelteKit with enforce: 'pre'
- Insert middleware at beginning of stack to catch malformed URIs early

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/backend/index.js

@@ -1,7 +1,7 @@
 import { Elysia, t } from 'elysia';
 import { cors } from '@elysiajs/cors';
 import { jwt } from '@elysiajs/jwt';
-import { JWT_SECRET, logger, LOG_LEVEL } from './config.js';
+import { JWT_SECRET, logger, LOG_LEVEL, logToFrontend } from './config.js';
 import {
   registerUser,
   authenticateUser,
@@ -79,6 +79,44 @@ const app = new Elysia()
     }
   })
 
+  // Request logging middleware
+  .onRequest(({ request, params }) => {
+    const url = new URL(request.url);
+    const method = request.method;
+    const path = url.pathname;
+    const query = url.search;
+
+    // Skip logging for health checks in development to reduce noise
+    if (path === '/api/health' && process.env.NODE_ENV === 'development') {
+      return;
+    }
+
+    logger.info('Incoming request', {
+      method,
+      path,
+      query: query || undefined,
+      ip: request.headers.get('x-forwarded-for') || 'unknown',
+      userAgent: request.headers.get('user-agent')?.substring(0, 100),
+    });
+  })
+  .onAfterHandle(({ request, set }) => {
+    const url = new URL(request.url);
+    const path = url.pathname;
+
+    // Skip logging for health checks in development
+    if (path === '/api/health' && process.env.NODE_ENV === 'development') {
+      return;
+    }
+
+    // Log error responses
+    if (set.status >= 400) {
+      logger.warn('Request failed', {
+        path,
+        status: set.status,
+      });
+    }
+  })
+
   /**
    * POST /api/auth/register
    * Register a new user
@@ -706,6 +744,47 @@ const app = new Elysia()
     timestamp: new Date().toISOString(),
   }))
 
+  /**
+   * POST /api/logs
+   * Receive frontend logs and write them to frontend.log file
+   */
+  .post(
+    '/api/logs',
+    async ({ body, user, headers }) => {
+      // Extract context from headers (Elysia provides headers as a plain object)
+      const userAgent = headers['user-agent'] || 'unknown';
+      const context = {
+        userId: user?.id,
+        userAgent,
+        timestamp: new Date().toISOString(),
+      };
+
+      // Log each entry
+      const entries = Array.isArray(body) ? body : [body];
+      for (const entry of entries) {
+        logToFrontend(entry.level || 'info', entry.message || 'No message', entry.data || null, context);
+      }
+
+      return { success: true };
+    },
+    {
+      body: t.Union([
+        t.Object({
+          level: t.Optional(t.Union([t.Literal('debug'), t.Literal('info'), t.Literal('warn'), t.Literal('error')])),
+          message: t.String(),
+          data: t.Optional(t.Any()),
+        }),
+        t.Array(
+          t.Object({
+            level: t.Optional(t.Union([t.Literal('debug'), t.Literal('info'), t.Literal('warn'), t.Literal('error')])),
+            message: t.String(),
+            data: t.Optional(t.Any()),
+          })
+        ),
+      ]),
+    }
+  )
+
   // Serve static files and SPA fallback for all non-API routes
   .get('/*', ({ request }) => {
     const url = new URL(request.url);