⚡ perf(vscode): 开会话去掉多余远程往返，spinner 跟随真实进度

开会话原先要先全量拉工单（含每张工单的评论、依赖、PR）做前置锁检查，
再各读一次 state JSON 给 pre-create 钩子和终端图标，几秒后才 createTerminal。

- 锁检查改用主进程已算好的工单快照，快照里没有该工单才回落全量拉取
- state JSON 一次读两处用，且提前发起与本地准备重叠
- 会话行 spinner 由扩展的 session/tab-settled 消息驱动，不再是固定 1.5s 假动画，
  消息丢失时 60s 超时兜底

Claude-Session: https://claude.ai/code/session_01Kgmb1LvrPmFX3NoUDB4zZC

vscode/src/panel/handlers/sessions.ts

@@ -73,6 +73,20 @@ export async function handleResumeSession(panel: KanbanWebviewPanel, sessionId:
       existing.show(false)
       return
     }
+    // state JSON 一次读、两处用（钩子的 branch + 终端图标颜色）。提前发起，
+    // 让这趟远程往返和后面的本地准备工作重叠；读失败为 null，两处各自退化。
+    const statePromise: Promise<Record<string, unknown> | null> | undefined
+      = issueNumber !== undefined
+        ? panel.readIssueState(issueNumber).catch((err) => {
+            logger.add({
+              level: 'warn',
+              source: 'panel',
+              message: `resume #${issueNumber} 读 state JSON 失败`,
+              details: err instanceof Error ? err.message : String(err),
+            })
+            return null
+          })
+        : undefined
     // 实施 / 头脑风暴各自独立：调用方传入对应字段，空 = DEFAULT。
     const effectiveProfilePath
       = sessionKind === 'implement'
@@ -127,28 +141,10 @@ export async function handleResumeSession(panel: KanbanWebviewPanel, sessionId:
     // (issueNumber === undefined) 钩子签名要 issueNumber，同样跳过。
     if (sessionKind === 'implement' && !worktreeMissing && issueNumber !== undefined && workspaceRoot) {
       const settingsForHook = getSettings(panel.context)
-      // 从 state JSON 读 branch；任何一步读不到就用空字符串（脚本里
-      // BRANCH env 仍能传，只是为空），不阻塞 resume 主流程。
-      let branchForHook = ''
-      try {
-        const remote = await detectRepo(workspaceRoot)
-        if (remote) {
-          const token = await getToken(panel.context, remote.host)
-          if (token) {
-            const stateObj = await panel.readIssueState(issueNumber)
-            if (stateObj && typeof stateObj.branch === 'string')
-              branchForHook = stateObj.branch
-          }
-        }
-      }
-      catch (err) {
-        logger.add({
-          level: 'warn',
-          source: 'panel',
-          message: `resume #${issueNumber} 读 state JSON 失败，钩子 branch 用空字符串`,
-          details: err instanceof Error ? err.message : String(err),
-        })
-      }
+      // 从 state JSON 读 branch；读不到就用空字符串（脚本里 BRANCH env 仍能
+      // 传，只是为空），不阻塞 resume 主流程。
+      const stateObj = await statePromise
+      const branchForHook = typeof stateObj?.branch === 'string' ? stateObj.branch : ''
       await panel.dispatchWorktreeHook('impl-tab-pre-create', {
         workspaceRoot,
         worktreePath: effectiveCwd!,
@@ -164,7 +160,7 @@ export async function handleResumeSession(panel: KanbanWebviewPanel, sessionId:
     // harmless in the editor tab, still useful if the same terminal ever
     // gets rendered in panel-view mode.
     const issueIcon = issueNumber !== undefined
-      ? await panel.resolveIssueIcon(issueNumber)
+      ? await panel.resolveIssueIcon(issueNumber, await statePromise)
       : undefined
     const terminal = window.createTerminal({
       name: terminalName,
@@ -198,6 +194,8 @@ export async function handleResumeSession(panel: KanbanWebviewPanel, sessionId:
   finally {
     if (lockKey !== undefined)
       panel.resumeInFlight.delete(lockKey)
+    // 无论开成、复用已有 tab 还是被前置锁拒绝，都要告诉 webview 收 spinner。
+    panel.postMessage({ type: 'session/tab-settled', sessionId })
   }
 }
 
@@ -303,6 +301,7 @@ export async function handleResumeReviewSession(panel: KanbanWebviewPanel, sessi
   }
   finally {
     panel.resumeInFlight.delete(lockKey)
+    panel.postMessage({ type: 'session/tab-settled', sessionId })
   }
 }
 
@@ -1379,6 +1378,7 @@ export async function handleResumeTestSession(panel: KanbanWebviewPanel, session
   }
   finally {
     panel.resumeInFlight.delete(lockKey)
+    panel.postMessage({ type: 'session/tab-settled', sessionId })
   }
 }