feat(controller): 工具仓库、Skills 录入、多轮追问与终端运行日志

- 插件/MCP 改为通用工具仓库：内置、HTTP MCP、本机命令（stdio）三类工具，可增删改、
  按 Agent 分配；定义变更自动提升下发版本并重发，删除即回收分配并通知 Agent 清空。
- 旧 desktop-filesystem 降级为仓库中的一个内置条目；本机预设工具改为总控只展示、
  Agent 默认启用，任务执行来源新增 builtin（审计 task.builtin_tool_execution）。
- Skills 补齐录入闭环：新建或按名称覆盖更新，并可从旧版技能目录（SKILL.md + skill.json）
  批量导入；同名更新保持标识不变并自动重新应用，旧包入口脚本只提示不执行。
- 单独指派支持基于某条已完成任务的多轮追问：任务内容框仍下发无上下文的一次性任务，
  追问时由总控组装历史（仅成功轮次、默认最近 50 轮 / 约 6 万字符），会话按 Agent 隔离；
  执行动态把同一会话合并为一条记录，任务详情弹窗底部提供继续对话输入框。
- 任务详情支持运行中观测：打开期间每 2 秒刷新，终端风格输出全部事件并自动滚动；
  progress 事件不改变任务状态且顺延无进展超时，避免正在执行工具的任务被误判超时。
- 修复 build.ps1 缺 UTF-8 BOM 导致 build.bat 在 PowerShell 5.1 下语法报错。

controller/internal/controlplane/agent_directory.go

@@ -62,7 +62,7 @@ type AgentOperationalDetail struct {
 	Failures          []DeploymentFailure `json:"failures"`
 }
 
-const agentDirectoryBaseSQL = `WITH skill_summary AS (
+var agentDirectoryBaseSQL = `WITH skill_summary AS (
 	SELECT agent_id, COUNT(*) AS total,
 	SUM(CASE WHEN apply_status = 'applied' THEN 1 ELSE 0 END) AS applied,
 	SUM(CASE WHEN apply_status = 'failed' THEN 1 ELSE 0 END) AS failed,
@@ -82,13 +82,14 @@ const agentDirectoryBaseSQL = `WITH skill_summary AS (
 		WHEN COALESCE(s.sent, 0) > 0 THEN 'sent'
 		ELSE 'applied' END AS skill_status,
 	COALESCE(s.failure, '') AS skill_failure,
-	COALESCE(m.apply_status, '未启用') AS mcp_status, COALESCE(m.last_error, '') AS mcp_failure,
-	MAX(COALESCE(l.updated_at, ''), COALESCE(m.updated_at, ''), COALESCE(s.updated_at, '')) AS last_deployment_at
+	` + mcpStatusExpression("a.agent_id") + ` AS mcp_status,
+	` + mcpErrorExpression("a.agent_id") + ` AS mcp_failure,
+	COALESCE((SELECT MAX(updated_at) FROM agent_mcp_assignments m WHERE m.agent_id = a.agent_id), '') AS mcp_updated_at,
+	MAX(COALESCE(l.updated_at, ''), COALESCE((SELECT MAX(updated_at) FROM agent_mcp_assignments m WHERE m.agent_id = a.agent_id), ''), COALESCE(s.updated_at, '')) AS last_deployment_at
 	FROM managed_agents a
 	LEFT JOIN agent_llm_assignments l ON l.agent_id = a.agent_id
 	LEFT JOIN llm_profiles p ON p.profile_id = l.profile_id
 	LEFT JOIN skill_summary s ON s.agent_id = a.agent_id
-	LEFT JOIN agent_mcp_assignments m ON m.agent_id = a.agent_id AND m.tool_id = 'desktop-filesystem'
 )
 `
 
@@ -220,7 +221,7 @@ func (c *ControlPlane) AgentOperationalDetails(agentID string) (AgentOperational
 }
 
 func (c *ControlPlane) recentTasksForAgent(agentID string, maximum int) ([]Task, error) {
-	rows, err := c.db.Query("SELECT task_id, agent_id, COALESCE(NULLIF(agent_name, ''), '未知 Agent'), instruction, status, created_at, COALESCE(started_at, ''), COALESCE(finished_at, ''), COALESCE(deadline_at, ''), COALESCE(attempt, 1), COALESCE(retry_of, ''), COALESCE(output, ''), COALESCE(error, ''), COALESCE(execution_source, '') FROM task_runs WHERE agent_id = ? ORDER BY created_at DESC LIMIT ?", agentID, maximum)
+	rows, err := c.db.Query("SELECT task_id, agent_id, COALESCE(NULLIF(agent_name, ''), '未知 Agent'), instruction, status, created_at, COALESCE(started_at, ''), COALESCE(finished_at, ''), COALESCE(deadline_at, ''), COALESCE(attempt, 1), COALESCE(retry_of, ''), COALESCE(output, ''), COALESCE(error, ''), COALESCE(execution_source, ''), COALESCE(session_id, '') FROM task_runs WHERE agent_id = ? ORDER BY created_at DESC LIMIT ?", agentID, maximum)
 	if err != nil {
 		return nil, fmt.Errorf("无法读取 Agent 最近任务: %w", err)
 	}
@@ -228,7 +229,7 @@ func (c *ControlPlane) recentTasksForAgent(agentID string, maximum int) ([]Task,
 	tasks := make([]Task, 0)
 	for rows.Next() {
 		var task Task
-		if err := rows.Scan(&task.ID, &task.AgentID, &task.AgentName, &task.Instruction, &task.Status, &task.CreatedAt, &task.StartedAt, &task.FinishedAt, &task.DeadlineAt, &task.Attempt, &task.RetryOf, &task.Output, &task.Error, &task.Execution); err != nil {
+		if err := rows.Scan(&task.ID, &task.AgentID, &task.AgentName, &task.Instruction, &task.Status, &task.CreatedAt, &task.StartedAt, &task.FinishedAt, &task.DeadlineAt, &task.Attempt, &task.RetryOf, &task.Output, &task.Error, &task.Execution, &task.SessionID); err != nil {
 			return nil, err
 		}
 		tasks = append(tasks, task)