Add OpenCode Go/Zen API binding support

TelegramSearchBot.Common/Model/AI/AuthorizationSource.cs

@@ -0,0 +1,10 @@
+namespace TelegramSearchBot.Model.AI {
+    /// <summary>
+    /// ChannelWithModel 授权来源。Manual = 管理员手工添加，永不被刷新/目录结果软删；
+    /// Discovered = 来自授权快照来源，仅真正快照刷新成功后处理。
+    /// </summary>
+    public enum AuthorizationSource {
+        Manual = 0,
+        Discovered = 1
+    }
+}

TelegramSearchBot.Common/Model/AI/LlmAgentContracts.cs

@@ -76,6 +76,12 @@ public sealed class AgentChannelConfig {
         public int Priority { get; set; }
         public string ModelName { get; set; } = string.Empty;
         public List<AgentModelCapability> Capabilities { get; set; } = [];
+
+        // Phase 2：解析出的 binding 快照（旧二进制/legacy 行全部为 null，走 Provider/Gateway）。
+        public int? BindingId { get; set; }
+        public string BindingEndpoint { get; set; } = string.Empty;
+        public LlmProtocol? BindingProtocol { get; set; }
+        public LlmAuthProfile? BindingAuthProfile { get; set; }
     }
 
     public sealed class AgentExecutionTask {

TelegramSearchBot.Common/Model/AI/LlmAuthProfile.cs

@@ -0,0 +1,10 @@
+namespace TelegramSearchBot.Model.AI {
+    /// <summary>
+    /// API binding 的认证方式。key 本体仍共享自 LLMChannel.ApiKey。
+    /// </summary>
+    public enum LlmAuthProfile {
+        Bearer = 0,
+        AnthropicApiKey = 1,
+        None = 2
+    }
+}

TelegramSearchBot.Common/Model/AI/LlmProtocol.cs

@@ -0,0 +1,13 @@
+namespace TelegramSearchBot.Model.AI {
+    /// <summary>
+    /// API binding 的线协议。与 LLMProvider（品牌/订阅账号）语义分离，
+    /// 同一 channel 可通过多个 binding 支持不同协议。
+    /// </summary>
+    public enum LlmProtocol {
+        OpenAIChat = 0,
+        OpenAIResponses = 1,
+        AnthropicMessages = 2,
+        Ollama = 3,
+        Gemini = 4
+    }
+}