Harden and parallelize session listing

Replace deprecated fs.exists with stat, wrap git calls in try/catch
to gracefully degrade to "idle" for inaccessible worktrees, and load
all projects concurrently in loadAll. Also fix stale-lock retry in
withGlobalLock to re-attempt mkdir immediately after cleanup.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/commands/list.ts

@@ -1,6 +1,6 @@
 import { basename } from "path"
 import { homedir } from "os"
-import { exists } from "fs/promises"
+import { stat } from "fs/promises"
 import * as git from "../git.ts"
 import * as vm from "../vm.ts"
 import * as state from "../state.ts"
@@ -47,16 +47,20 @@ async function resolveStatus(
   s: { branch: string; worktree: string; in_review?: boolean },
   vmRunning: boolean,
 ): Promise<string> {
-  if (!(await exists(s.worktree))) return "idle"
+  try { await stat(s.worktree) } catch { return "idle" }
   if (vmRunning) {
     const active = await vm.isClaudeActive(s.worktree, s.branch)
     if (active && s.in_review) return "review"
     if (active) return "active"
   }
-  const dirty = await git.isDirty(s.worktree)
-  if (dirty) return "dirty"
-  const commits = await git.hasNewCommits(s.worktree)
-  return commits ? "saved" : "idle"
+  try {
+    const dirty = await git.isDirty(s.worktree)
+    if (dirty) return "dirty"
+    const commits = await git.hasNewCommits(s.worktree)
+    return commits ? "saved" : "idle"
+  } catch {
+    return "idle"
+  }
 }
 
 async function resolveAllStatuses<T extends { branch: string; worktree: string; in_review?: boolean; repoRoot: string }>(
@@ -135,16 +139,13 @@ export async function action(opts: { json?: boolean; all?: boolean; add?: string
     sessions = Object.values(st.sessions).map(s => ({ ...s, repoRoot: root }))
   }
 
+  const vmRunning = (await vm.status()) === "running"
+
   if (sessions.length === 0 && !opts.json) {
     console.log(opts.all ? "◆ No active sessions across any project." : "◆ No active sessions.")
-    if (!opts.all) {
-      const vmRunning = (await vm.status()) === "running"
-      if (!vmRunning) console.log(`\n${red}VM is not running.${reset}`)
-    }
+    if (!opts.all && !vmRunning) console.log(`\n${red}VM is not running.${reset}`)
     return
   }
-
-  const vmRunning = (await vm.status()) === "running"
   await backfillPrompts(sessions, vmRunning)
 
   // Key by repoRoot/branch to avoid collisions across repos with the same basename

src/state.ts

@@ -66,11 +66,9 @@ const GLOBAL_STATE_PATH = join(GLOBAL_DIR, "registry.json")
 async function withGlobalLock<T>(fn: () => Promise<T>): Promise<T> {
   const lockPath = join(GLOBAL_DIR, "registry.lock")
   await mkdir(GLOBAL_DIR, { recursive: true })
-  let acquired = false
   for (let i = 0; i < 20; i++) {
     try {
       await mkdir(lockPath)
-      acquired = true
       break
     } catch {
       // If the lock is older than 5 minutes, assume it's stale (crashed process)
@@ -78,7 +76,11 @@ async function withGlobalLock<T>(fn: () => Promise<T>): Promise<T> {
         const info = await stat(lockPath)
         if (Date.now() - info.mtimeMs > 300_000) {
           await rmdir(lockPath).catch(() => {})
-          continue
+          // Retry mkdir immediately instead of continuing the loop
+          try {
+            await mkdir(lockPath)
+            break
+          } catch {}
         }
       } catch {}
       if (i === 19) throw new Error("Could not acquire registry lock")
@@ -196,27 +198,38 @@ export async function loadAll(): Promise<GlobalSession[]> {
   const all: GlobalSession[] = []
   const stale: string[] = []
 
-  for (const project of gs.projects) {
-    const st = await load(project)
+  const results = await Promise.all(gs.projects.map(async (project) => {
+    let st: State
+    try {
+      st = await load(project)
+    } catch {
+      return { project, stale: true } as const
+    }
     if (Object.keys(st.sessions).length === 0) {
-      // Check if the state file actually exists — if not, this project is stale
       const file = Bun.file(join(project, ".sandlot", "state.json"))
       if (!(await file.exists())) {
-        stale.push(project)
-        continue
+        return { project, stale: true } as const
       }
     }
     const repo = basename(project)
-    for (const session of Object.values(st.sessions)) {
-      all.push({ ...session, repo, repoRoot: project })
+    const sessions = Object.values(st.sessions).map(s => ({ ...s, repo, repoRoot: project }))
+    return { project, stale: false, sessions } as const
+  }))
+
+  for (const r of results) {
+    if (r.stale) {
+      stale.push(r.project)
+    } else if ('sessions' in r) {
+      all.push(...r.sessions)
     }
   }
 
   // Prune projects whose state files no longer exist
   if (stale.length > 0) {
+    const staleSet = new Set(stale)
     await withGlobalLock(async () => {
       const fresh = await loadGlobal()
-      fresh.projects = fresh.projects.filter(p => !stale.includes(p))
+      fresh.projects = fresh.projects.filter(p => !staleSet.has(p))
       await saveGlobal(fresh)
     }).catch(() => {})
   }