Replace magic numbers with named constants in server

Refactoring: Extract magic numbers to named constants
- MAX_BATCH_SIZE = 100 (batch request limit)
- MAX_PAGE_SIZE = 100 (pagination limit)

Replaced in:
- app.ts: Batch size validation (line 68-69)
- rpc.ts: Page size limit (line 184)

Impact: Improves code clarity and makes limits configurable

src/app.ts

@@ -4,6 +4,9 @@ import { Storage } from './storage/types.ts';
 import { Config } from './config.ts';
 import { handleRpc, RpcRequest } from './rpc.ts';
 
+// Constants
+const MAX_BATCH_SIZE = 100;
+
 /**
  * Creates the Hono application with RPC interface
  */
@@ -62,8 +65,8 @@ export function createApp(storage: Storage, config: Config) {
         return c.json({ error: 'Empty request array' }, 400);
       }
 
-      if (requests.length > 100) {
-        return c.json({ error: 'Too many requests in batch (max 100)' }, 400);
+      if (requests.length > MAX_BATCH_SIZE) {
+        return c.json({ error: `Too many requests in batch (max ${MAX_BATCH_SIZE})` }, 400);
       }
 
       // Handle RPC

src/rpc.ts

@@ -12,6 +12,9 @@ import {
   validateUsername,
 } from './crypto.ts';
 
+// Constants
+const MAX_PAGE_SIZE = 100;
+
 /**
  * RPC request format
  */
@@ -178,7 +181,7 @@ const handlers: Record<string, RpcHandler> = {
 
     // Paginated discovery mode
     if (limit !== undefined) {
-      const pageLimit = Math.min(Math.max(1, limit), 100);
+      const pageLimit = Math.min(Math.max(1, limit), MAX_PAGE_SIZE);
       const pageOffset = Math.max(0, offset || 0);
 
       const allServices = await storage.getServicesByName(