refactor: unify server-agent to new pattern

- Change field names to snake_case (user_id, collected_info, last_recommendation, created_at, updated_at, expires_at)
- Extract system prompts to constants (SERVER_EXPERT_PROMPT, SERVER_REVIEW_PROMPT)
- Add __PASSTHROUGH__/__SESSION_END__ marker support
- Change handler signature to match other agents (db, userId, userMessage, env, options)
- Add helper functions for consistency (createServerSession, isSessionExpired, addMessageToSession, hasServerSession)
- Update saveSe rverSession signature to not need userId separately
- Rename tools constant from serverExpertTools to serverExpertTools (camelCase)
- Change AI call parameter order for consistency
- Add performance logging
- Update openai-service.ts routing to use hasServerSession
- Update server-tool.ts to use new session creation helpers
- Update message-handler.ts and api/chat.ts field references

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

src/openai-service.ts

@@ -6,7 +6,7 @@ import { createLogger } from './utils/logger';
 import { metrics } from './utils/metrics';
 import { getOpenAIUrl } from './utils/api-urls';
 import { ERROR_MESSAGES } from './constants/messages';
-import { getServerSession, processServerConsultation } from './agents/server-agent';
+import { hasServerSession, processServerConsultation } from './agents/server-agent';
 import { processTroubleshootConsultation, hasTroubleshootSession } from './agents/troubleshoot-agent';
 import { processDomainConsultation, hasDomainSession } from './agents/domain-agent';
 import { processDepositConsultation, hasDepositSession } from './agents/deposit-agent';
@@ -210,13 +210,11 @@ export async function generateOpenAIResponse(
   // Check if server consultation session is active
   if (telegramUserId && env.DB) {
     try {
-      const session = await getServerSession(env.DB, telegramUserId);
+      const hasSession = await hasServerSession(env.DB, telegramUserId);
 
-      if (session && session.status !== 'completed') {
+      if (hasSession) {
         logger.info('Active server session detected, routing to consultation', {
-          userId: telegramUserId,
-          status: session.status,
-          hasLastRecommendation: !!session.lastRecommendation
+          userId: telegramUserId
         });
 
         // Create callback for intermediate messages
@@ -229,7 +227,13 @@ export async function generateOpenAIResponse(
           };
         }
 
-        const result = await processServerConsultation(userMessage, session, env, sendIntermediateMessage);
+        const result = await processServerConsultation(
+          env.DB,
+          telegramUserId,
+          userMessage,
+          env,
+          { sendIntermediateMessage }
+        );
 
         // PASSTHROUGH: 무관한 메시지는 일반 처리로 전환
         if (result !== '__PASSTHROUGH__') {