feat(web): adopt @vincjo/datatables for all tables, standardize shared components

- Add DataTable.svelte: declarative columns, built-in sorting, sticky headers,
  text truncation, column alignment, configurable widths, optional pagination/search
- 12 built-in renderers: BadgeRenderer, StatusBadgeRenderer (unified risk/severity/
  execution/state/type variant mapping), HealthDotRenderer, RelativeTimeRenderer,
  DateRenderer, DurationRenderer, StatusDotRenderer, SignalActions, ApprovalActions,
  ActivityAction, ActivityCancel
- Migrate Overview (task board), Signals, Ops (3 tables) to DataTable
- Refactor EntityTable treegrid to use shared SortHeader, EmptyState, HealthDotRenderer
- Create shared components: EmptyState, StatusBadge, FilterTabs
- Clean up Knowledge.svelte: replace inline relTime() and typeVariant() with shared utils
- Add width, align, truncate column props; table-fixed layout; rounded-xl borders
- Bump version to 0.11.0

web/src/lib/components/data-table/renderers/StatusBadgeRenderer.svelte

@@ -0,0 +1,49 @@
+<script lang="ts">
+  import { Badge } from '$lib/components/ui/badge'
+
+  let { value, kind = 'default' }: { value: unknown; kind?: 'risk' | 'severity' | 'execution' | 'state' | 'type' | 'default' } = $props()
+
+  const v = $derived(String(value ?? ''))
+
+  const variantMap: Record<string, Record<string, 'default' | 'secondary' | 'destructive' | 'outline'>> = {
+    risk: {
+      destructive: 'destructive',
+      config_mutation: 'secondary',
+      default: 'default',
+    },
+    severity: {
+      critical: 'destructive',
+      warning: 'secondary',
+      info: 'default',
+      default: 'default',
+    },
+    execution: {
+      failed: 'destructive',
+      denied: 'destructive',
+      revoked: 'destructive',
+      cancelled: 'destructive',
+      completed: 'default',
+      running: 'secondary',
+      approved: 'secondary',
+      default: 'outline',
+    },
+    state: {
+      active: 'default',
+      healthy: 'default',
+      default: 'outline',
+    },
+    type: {
+      runbook: 'secondary',
+      investigation: 'default',
+      default: 'outline',
+    },
+    default: { default: 'default' },
+  }
+
+  const variant = $derived.by(() => {
+    const map = variantMap[kind] ?? variantMap.default
+    return (map[v] ?? map.default) as 'default' | 'secondary' | 'destructive' | 'outline'
+  })
+</script>
+
+<Badge {variant}>{v}</Badge>