fix: address PR bot review comments

Critical fixes:
- Fix duplicated isPolling/pollLastTouched in events route (missing closing brace)
- Add missing path import to realtime.ts (path.basename was used without import)
- Fix error.message leak in sessions and beads/read routes (security)
- Add missing NextResponse import to activity route
- Fix diffDependencies to use composite key (type:target) for accurate tracking

Code quality:
- Fix beadCounts computation in kanban-controls (was counting epic's own deps, not child issues)
- Replace require('path') with ES module imports throughout

Tests: 13/15 passing (2 contract tests remain brittle)

Co-authored-by: openhands <openhands@all-hands.dev>

src/components/kanban/kanban-controls.tsx

@@ -1,5 +1,6 @@
 'use client';
 
+import { useMemo } from 'react';
 import { motion } from 'framer-motion';
 
 import type { KanbanFilterOptions, KanbanStats } from '../../lib/kanban';
@@ -12,6 +13,7 @@ interface KanbanControlsProps {
   filters: KanbanFilterOptions;
   stats: KanbanStats;
   epics: BeadIssue[];
+  issues: BeadIssue[];
   onFiltersChange: (filters: KanbanFilterOptions) => void;
   onNextActionable: () => void;
   nextActionableFeedback?: string | null;
@@ -21,6 +23,7 @@ export function KanbanControls({
   filters,
   stats,
   epics,
+  issues,
   onFiltersChange,
   onNextActionable,
   nextActionableFeedback = null,
@@ -29,12 +32,24 @@ export function KanbanControls({
     'ui-field rounded-xl px-3 py-2.5 text-sm outline-none transition';
 
   // Build bead counts map for EpicChipStrip
-  const beadCounts = new Map<string, number>();
-  for (const epic of epics) {
-    // Count non-epic issues that belong to this epic
-    const count = epic.dependencies?.filter(d => d.type === 'parent' && d.target === epic.id).length ?? 0;
-    beadCounts.set(epic.id, count);
-  }
+  // Count non-epic issues that have this epic as their parent
+  const beadCounts = useMemo(() => {
+    const counts = new Map<string, number>();
+    for (const epic of epics) {
+      let count = 0;
+      for (const issue of issues) {
+        if (issue.issue_type === 'epic') continue;
+        const parentDep = issue.dependencies.find(d => d.type === 'parent');
+        const inferredParent = issue.id.includes('.') ? issue.id.split('.')[0] : null;
+        const parentEpicId = parentDep?.target ?? inferredParent;
+        if (parentEpicId === epic.id) {
+          count++;
+        }
+      }
+      counts.set(epic.id, count);
+    }
+    return counts;
+  }, [epics, issues]);
 
   return (
     <section className="grid gap-3">

src/components/kanban/kanban-page.tsx

@@ -230,6 +230,7 @@ export function KanbanPage({
         filters={filters}
         stats={stats}
         epics={localIssues.filter((issue) => issue.issue_type === 'epic')}
+        issues={localIssues}
         onFiltersChange={setFilters}
         onNextActionable={handleNextActionable}
         nextActionableFeedback={nextActionableFeedback}