feat: 添加 /goal 命令，支持长时间运行任务的目标管理 (#1222)

* feat: 添加 /goal 命令，支持长时间运行任务的目标管理

从 Codex 项目移植 /goal 命令到 Claude Code，实现：
- Goal 状态管理模块（active/paused/budget_limited/complete）
- /goal 斜杠命令（set/clear/pause/resume/complete）
- Goal 模型工具（get/set/complete）
- Continuation prompt 自动注入系统提示
- Token 用量自动追踪

Co-Authored-By: mimo-v2.5-pro <XiaomiMiMo@claude-code-best.win>

* fix: goal 状态改为 session-scoped，避免多会话泄漏

将 currentGoal 单例替换为 Map<string, GoalState>，按 sessionId 隔离，
遵循 sessionIngress.ts 的模式。所有函数支持可选 sessionId 参数。

Co-Authored-By: mimo-v2.5-pro <XiaomiMiMo@claude-code-best.win>

* fix: 对 goal 的 tokenBudget/tokensUsed 添加数值校验

setGoal 中 tokenBudget 非 finite 或负数时归零；
updateGoalTokens 中 usage 非 finite 或负数时归零。

Co-Authored-By: mimo-v2.5-pro <XiaomiMiMo@claude-code-best.win>

* fix: 暂停期间 goal 时间不再继续计数

新增 pausedAt/accumulatedActiveMs 字段，pauseGoal 累积已活跃时间，
resumeGoal 重置 startTime，计时统一使用 getActiveElapsedMs()。

Co-Authored-By: mimo-v2.5-pro <XiaomiMiMo@claude-code-best.win>

---------

Co-authored-by: mimo-v2.5-pro <XiaomiMiMo@claude-code-best.win>

src/commands/goal/goal.ts

@@ -0,0 +1,66 @@
+import type { LocalCommandCall } from '../../types/command.js'
+import {
+  clearGoal,
+  completeGoal,
+  formatGoalStatus,
+  getGoal,
+  pauseGoal,
+  resumeGoal,
+  setGoal,
+} from '../../services/goal/goalState.js'
+
+export const call: LocalCommandCall = async args => {
+  const trimmed = args.trim()
+
+  // No arguments — show current goal status
+  if (!trimmed) {
+    return { type: 'text', value: formatGoalStatus() }
+  }
+
+  const lower = trimmed.toLowerCase()
+
+  // Control subcommands
+  if (lower === 'clear') {
+    const goal = getGoal()
+    if (!goal) {
+      return { type: 'text', value: 'No active goal to clear.' }
+    }
+    clearGoal()
+    return { type: 'text', value: 'Goal cleared.' }
+  }
+
+  if (lower === 'pause') {
+    if (pauseGoal()) {
+      return { type: 'text', value: 'Goal paused.' }
+    }
+    return { type: 'text', value: 'No active goal to pause.' }
+  }
+
+  if (lower === 'resume') {
+    if (resumeGoal()) {
+      return { type: 'text', value: 'Goal resumed.' }
+    }
+    return { type: 'text', value: 'No paused goal to resume.' }
+  }
+
+  if (lower === 'complete') {
+    if (completeGoal()) {
+      return { type: 'text', value: 'Goal marked as complete.' }
+    }
+    return { type: 'text', value: 'No active goal to complete.' }
+  }
+
+  // Set a new goal
+  const existing = getGoal()
+  if (existing && existing.status === 'active') {
+    // Replace existing active goal
+    setGoal(trimmed)
+    return {
+      type: 'text',
+      value: `Goal replaced.\n\n${formatGoalStatus()}`,
+    }
+  }
+
+  setGoal(trimmed)
+  return { type: 'text', value: `Goal set.\n\n${formatGoalStatus()}` }
+}

src/commands/goal/index.ts

@@ -0,0 +1,12 @@
+import type { Command } from '../../commands.js'
+
+const goal = {
+  type: 'local',
+  name: 'goal',
+  description: 'Set or view the goal for a long-running task',
+  supportsNonInteractive: true,
+  argumentHint: '<objective> | clear | pause | resume',
+  load: () => import('./goal.js'),
+} satisfies Command
+
+export default goal