feat: add performance controls for large browser ops

- Add throttled large-operation handling for tab, group, and session commands.
- Introduce performance profiles, audible-tab aware gentle mode, and job progress tracking.
- Support background session restores with status/cancel commands and lazy placeholders.
- Expose new perf and extension CLI groups plus matching Python SDK methods.
- Preserve pinned tabs during session snapshots and debounce auto-save updates.
- Bump browser-cli and extension versions to 0.10.0 and add pytest-cov to dev deps.
- Add coverage for performance controls, background jobs, lazy restores, and tab metadata.

extension/src/commands/groups.ts

@@ -1,5 +1,5 @@
 // @ts-nocheck
-import { buildTabBlocks, resolveGroupId, tabInfo } from '../core';
+import { buildTabBlocks, getLargeOperationThrottle, resolveGroupId, runLargeOperation, tabInfo, throwIfJobCancelled, updateJobProgress, yieldForLargeOperation } from '../core';
 export async function groupList() {
   const groups = await chrome.tabGroups.query({});
   const all = await chrome.tabs.query({});
@@ -29,11 +29,21 @@ export async function groupQuery({ search }) {
   return groups.filter(g => g.title && g.title.toLowerCase().includes(q));
 }
 
-export async function groupClose({ groupId }) {
-  const tabs = await chrome.tabs.query({});
-  const groupTabs = tabs.filter(t => t.groupId === groupId);
-  await chrome.tabs.ungroup(groupTabs.map(t => t.id));
-  return { groupId };
+export async function groupClose({ groupId, gentleMode, __job } = {}) {
+  return runLargeOperation("group.close", async () => {
+    const tabs = await chrome.tabs.query({});
+    const groupTabs = tabs.filter(t => t.groupId === groupId);
+    const tabIds = groupTabs.map(t => t.id);
+    const throttle = await getLargeOperationThrottle(tabIds.length, gentleMode);
+    updateJobProgress(__job, { phase: "ungrouping tabs", current: 0, total: tabIds.length });
+    for (let i = 0; i < tabIds.length; i += throttle.batchSize) {
+      throwIfJobCancelled(__job);
+      await chrome.tabs.ungroup(tabIds.slice(i, i + throttle.batchSize));
+      updateJobProgress(__job, { phase: "ungrouping tabs", current: Math.min(i + throttle.batchSize, tabIds.length), total: tabIds.length });
+      await yieldForLargeOperation(i + throttle.batchSize, throttle.batchSize, throttle.pauseMs);
+    }
+    return { groupId, gentle: throttle.gentle, audible: throttle.audible };
+  });
 }
 
 export async function groupOpen({ name }) {