feat: add database migration v9→v10 for Hermes support (Phase 2)

- Bump SCHEMA_VERSION from 9 to 10
- Add enabled_hermes column to mcp_servers and skills tables
- Add migrate_v9_to_v10 with table_exists guard for skills (may not
  exist in databases migrated from very old versions)
- Update dao/mcp.rs to fully read/write enabled_hermes in all queries
- Update dao/skills.rs: don't SELECT enabled_hermes (Hermes doesn't
  support Skills yet), keep column indices clean

src-tauri/src/database/schema.rs

@@ -65,7 +65,8 @@ impl Database {
             id TEXT PRIMARY KEY, name TEXT NOT NULL, server_config TEXT NOT NULL,
             description TEXT, homepage TEXT, docs TEXT, tags TEXT NOT NULL DEFAULT '[]',
             enabled_claude BOOLEAN NOT NULL DEFAULT 0, enabled_codex BOOLEAN NOT NULL DEFAULT 0,
-            enabled_gemini BOOLEAN NOT NULL DEFAULT 0, enabled_opencode BOOLEAN NOT NULL DEFAULT 0
+            enabled_gemini BOOLEAN NOT NULL DEFAULT 0, enabled_opencode BOOLEAN NOT NULL DEFAULT 0,
+            enabled_hermes BOOLEAN NOT NULL DEFAULT 0
         )",
             [],
         )
@@ -93,6 +94,7 @@ impl Database {
             enabled_codex BOOLEAN NOT NULL DEFAULT 0,
             enabled_gemini BOOLEAN NOT NULL DEFAULT 0,
             enabled_opencode BOOLEAN NOT NULL DEFAULT 0,
+            enabled_hermes BOOLEAN NOT NULL DEFAULT 0,
             installed_at INTEGER NOT NULL DEFAULT 0,
             content_hash TEXT,
             updated_at INTEGER NOT NULL DEFAULT 0
@@ -423,6 +425,11 @@ impl Database {
                         Self::migrate_v8_to_v9(conn)?;
                         Self::set_user_version(conn, 9)?;
                     }
+                    9 => {
+                        log::info!("迁移数据库从 v9 到 v10（添加 Hermes Agent 支持）");
+                        Self::migrate_v9_to_v10(conn)?;
+                        Self::set_user_version(conn, 10)?;
+                    }
                     _ => {
                         return Err(AppError::Database(format!(
                             "未知的数据库版本 {version}，无法迁移到 {SCHEMA_VERSION}"
@@ -1168,6 +1175,29 @@ impl Database {
         Ok(())
     }
 
+    /// v9 -> v10 迁移：添加 Hermes Agent 支持
+    fn migrate_v9_to_v10(conn: &Connection) -> Result<(), AppError> {
+        Self::add_column_if_missing(
+            conn,
+            "mcp_servers",
+            "enabled_hermes",
+            "BOOLEAN NOT NULL DEFAULT 0",
+        )?;
+
+        // skills table may not exist in databases migrated from very old versions
+        if Self::table_exists(conn, "skills")? {
+            Self::add_column_if_missing(
+                conn,
+                "skills",
+                "enabled_hermes",
+                "BOOLEAN NOT NULL DEFAULT 0",
+            )?;
+        }
+
+        log::info!("v9 -> v10 迁移完成：已添加 Hermes Agent 支持");
+        Ok(())
+    }
+
     /// 插入默认模型定价数据
     /// 格式: (model_id, display_name, input, output, cache_read, cache_creation)
     /// 注意: model_id 使用短横线格式（如 claude-haiku-4-5），与 API 返回的模型名称标准化后一致