修复 Kimi 对话结束后未销毁对话的问题

forwarder.ts 中 realChatId.startsWith('kimi-') 的守卫误杀了服务端
返回的合法 chat ID，导致 deleteConversation 从未执行。
移除该守卫，getConversationId() 已正确处理空值情况。

同时清理 kimi.ts 中 getConversationId() 的死代码（conversationId
始终为空字符串，fallback 路径永远不会触发）。

Co-Authored-By: DeepSeek V4 Pro <noreply@deepseek.com>

Author: bennylii

src/main/proxy/adapters/kimi.ts

@@ -426,15 +426,9 @@ export class KimiStreamHandler {
   }
 
   getConversationId(): string | null {
-    // Return realChatId if available, otherwise return null (not empty string)
-    // to prevent saving invalid session IDs
     if (this.realChatId) {
       return this.realChatId
     }
-    // Only return conversationId if it's a valid ID (not empty and not a temporary ID)
-    if (this.conversationId && this.conversationId.length > 0 && !this.conversationId.startsWith('kimi-')) {
-      return this.conversationId
-    }
     return null
   }
 

src/main/proxy/forwarder.ts

@@ -828,7 +828,7 @@ CRITICAL RULES:
           const originalEnd = transformedStream.end.bind(transformedStream)
           transformedStream.end = function(chunk?: any, encoding?: any, callback?: any) {
             const realChatId = handler.getConversationId()
-            if (realChatId && realChatId.startsWith('kimi-') === false) {
+            if (realChatId) {
               adapter.deleteConversation(realChatId).catch(err => {
                 console.error('[Kimi] Failed to delete conversation:', err)
               })
@@ -854,7 +854,7 @@ CRITICAL RULES:
 
       if (shouldDeleteSession()) {
         const realChatId = handler.getConversationId()
-        if (realChatId && realChatId.startsWith('kimi-') === false) {
+        if (realChatId) {
           await adapter.deleteConversation(realChatId)
         }
       }