chore: 移除 bootstrap/state.ts 中 4 个未引用的 export

- clearRegisteredHooks（STATE.registeredHooks 仍由其他函数管理）
- getInvokedSkills（getInvokedSkillsForAgent 是活跃入口）
- getSessionSource（setSessionSource 仍活跃，sessionSource state 字段保留）
- markScrollActivity（scrollDraining/getIsScrollDraining/waitForScrollDrain 仍活跃）

仅删除孤儿访问器，不动模块级 state 副作用。

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/bootstrap/state.ts

@@ -787,18 +787,6 @@ let scrollDraining = false
 let scrollDrainTimer: ReturnType<typeof setTimeout> | undefined
 const SCROLL_DRAIN_IDLE_MS = 150
 
-/** Mark that a scroll event just happened. Background intervals gate on
- *  getIsScrollDraining() and skip their work until the debounce clears. */
-export function markScrollActivity(): void {
-  scrollDraining = true
-  if (scrollDrainTimer) clearTimeout(scrollDrainTimer)
-  scrollDrainTimer = setTimeout(() => {
-    scrollDraining = false
-    scrollDrainTimer = undefined
-  }, SCROLL_DRAIN_IDLE_MS)
-  scrollDrainTimer.unref?.()
-}
-
 /** True while scroll is actively draining (within 150ms of last event).
  *  Intervals should early-return when this is set — the work picks up next
  *  tick after scroll settles. */
@@ -1103,10 +1091,6 @@ export function setUserMsgOptIn(value: boolean): void {
   STATE.userMsgOptIn = value
 }
 
-export function getSessionSource(): string | undefined {
-  return STATE.sessionSource
-}
-
 export function setSessionSource(source: string): void {
   STATE.sessionSource = source
 }
@@ -1433,10 +1417,6 @@ export function getRegisteredHooks(): Partial<
   return STATE.registeredHooks
 }
 
-export function clearRegisteredHooks(): void {
-  STATE.registeredHooks = null
-}
-
 export function clearRegisteredPluginHooks(): void {
   if (!STATE.registeredHooks) {
     return
@@ -1527,10 +1507,6 @@ export function addInvokedSkill(
   })
 }
 
-export function getInvokedSkills(): Map<string, InvokedSkillInfo> {
-  return STATE.invokedSkills
-}
-
 export function getInvokedSkillsForAgent(
   agentId: string | undefined | null,
 ): Map<string, InvokedSkillInfo> {