fix: approval pill count mismatch with duplicate MCP tool names

When multiple MCP servers expose tools with the same name, the approval
pill showed an incorrect count (e.g. 150/300) even when everything was
approved.  The numerator used a Set<string> to deduplicate by tool ID,
so shared tools were counted once, while the denominator counted each
group occurrence independently.

Extract countApprovedToolsInGroups() into shared/domain/tooling.ts and
switch to per-group counting that mirrors the totalItemCount formula.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/components/ChatPane.tsx

@@ -30,6 +30,7 @@ import { type PatternDefinition, type ReasoningEffort } from '@shared/domain/pat
 import { isScratchpadProject, type ProjectRecord } from '@shared/domain/project';
 import { resolveSessionToolingSelection, type SessionBranchOriginAction, type SessionRecord } from '@shared/domain/session';
 import {
+  countApprovedToolsInGroups,
   groupApprovalToolsByProvider,
   listApprovalToolDefinitions,
   type RuntimeToolDefinition,
@@ -162,17 +163,7 @@ export function ChatPane({
   );
   const effectiveAutoApprovedCount = useMemo(() => {
     const groups = groupApprovalToolsByProvider(approvalTools, toolingSettings);
-    const counted = new Set<string>();
-    for (const group of groups) {
-      if (group.serverApprovalKey && effectiveAutoApproved.has(group.serverApprovalKey)) {
-        for (const tool of group.tools) counted.add(tool.id);
-      } else {
-        for (const tool of group.tools) {
-          if (effectiveAutoApproved.has(tool.id)) counted.add(tool.id);
-        }
-      }
-    }
-    return counted.size;
+    return countApprovedToolsInGroups(groups, effectiveAutoApproved);
   }, [approvalTools, effectiveAutoApproved, toolingSettings]);
   const isProbingMcp = (mcpProbingServerIds?.length ?? 0) > 0;
   const hasApprovalContent = approvalTools.length > 0 || isProbingMcp;