feat(frontend): add shared Badge component and dateFormat utility

Consolidation infrastructure:
- Badge.svelte: compact inline badge/chip with variant (success/warning/destructive/info/primary/muted), size, and dot mode
- dateFormat.ts: formatDate, formatDateTime, formatRelativeTime, formatFileSize — replaces 6+ local definitions
- Export Badge from $lib/ui index

frontend/src/lib/ui/Badge.svelte

@@ -0,0 +1,51 @@
+<!-- #region UI.Badge [C:2] [TYPE Component] [SEMANTICS badge,status,label,chip,tag,ui,atom] -->
+<!-- @ingroup UI -->
+<!-- @BRIEF Compact inline badge/chip for status, severity, and tag labels. -->
+<!-- @LAYER UI -->
+<!-- @RELATION USED_BY -> [Dashboard.RepositoryGrid] -->
+<!-- @RELATION USED_BY -> [TaskRunner] -->
+<!-- @RELATION USED_BY -> [ValidationFindingsPanel] -->
+<!-- @UX_STATE Default -> Colored pill with text label. -->
+<!-- @UX_STATE Dot -> Colored dot + label (for connection/task status). -->
+<script lang="ts">
+  let {
+    variant = "muted" as "success" | "warning" | "destructive" | "info" | "primary" | "muted",
+    size = "md" as "sm" | "md",
+    dot = false,
+    class: className = "",
+    children,
+  } = $props();
+
+  const variantClasses: Record<string, string> = {
+    success:     "bg-success-light text-success",
+    warning:     "bg-warning-light text-warning",
+    destructive: "bg-destructive-light text-destructive",
+    info:        "bg-info-light text-info",
+    primary:     "bg-primary-light text-primary",
+    muted:       "bg-surface-muted text-text-muted",
+  };
+
+  const sizeClasses: Record<string, string> = {
+    sm: "px-2 py-0.5",
+    md: "px-2.5 py-1",
+  };
+
+  const dotColorClasses: Record<string, string> = {
+    success:     "bg-success",
+    warning:     "bg-warning",
+    destructive: "bg-destructive",
+    info:        "bg-info",
+    primary:     "bg-primary-ring",
+    muted:       "bg-text-muted",
+  };
+</script>
+
+<span class="inline-flex items-center gap-1.5 {className}">
+  {#if dot}
+    <span class="h-2.5 w-2.5 rounded-full {dotColorClasses[variant] || dotColorClasses.muted}"></span>
+  {/if}
+  <span class="rounded-full {sizeClasses[size] || sizeClasses.md} text-xs font-medium {variantClasses[variant] || variantClasses.muted}">
+    {@render children?.()}
+  </span>
+</span>
+<!-- #endregion UI.Badge -->

frontend/src/lib/ui/index.ts

@@ -16,6 +16,7 @@ export { default as EmptyState } from './EmptyState.svelte';
 export { default as LanguageSwitcher } from './LanguageSwitcher.svelte';
 export { default as Icon } from './Icon.svelte';
 export { default as HelpTooltip } from './HelpTooltip.svelte';
+export { default as Badge } from './Badge.svelte';
 // [/SECTION: EXPORTS]
 
 // #endregion ui:Module

frontend/src/lib/utils/dateFormat.ts

@@ -0,0 +1,72 @@
+// #region Utils.DateFormat [C:2] [TYPE Module] [SEMANTICS date,format,utility,helper]
+// @ingroup Utils
+// @BRIEF Centralized date/time formatting utilities. Replaces 6+ local formatDate definitions.
+// @LAYER Infra
+// @RATIONALE 6 files defined independent formatDate functions and 20+ files use inline new Date().toLocaleDateString().
+//   Consolidating into one module ensures consistent locale-aware formatting and reduces duplication.
+
+// #region formatDate:Function [TYPE Function]
+// @BRIEF Format ISO date string to localized short date (e.g. "15 Jan 2025").
+export function formatDate(value: string | Date | null | undefined): string {
+  if (!value) return "";
+  const d = typeof value === "string" ? new Date(value) : value;
+  if (isNaN(d.getTime())) return "";
+  return d.toLocaleDateString(undefined, {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+  });
+}
+// #endregion formatDate:Function
+
+// #region formatDateTime:Function [TYPE Function]
+// @BRIEF Format ISO date string to localized date+time (e.g. "15 Jan 2025, 14:30").
+export function formatDateTime(value: string | Date | null | undefined): string {
+  if (!value) return "";
+  const d = typeof value === "string" ? new Date(value) : value;
+  if (isNaN(d.getTime())) return "";
+  return d.toLocaleDateString(undefined, {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+    hour: "2-digit",
+    minute: "2-digit",
+  });
+}
+// #endregion formatDateTime:Function
+
+// #region formatRelativeTime:Function [TYPE Function]
+// @BRIEF Format date to relative time string (e.g. "2 hours ago", "just now").
+export function formatRelativeTime(value: string | Date | null | undefined): string {
+  if (!value) return "";
+  const d = typeof value === "string" ? new Date(value) : value;
+  if (isNaN(d.getTime())) return "";
+
+  const now = Date.now();
+  const diffMs = now - d.getTime();
+  const diffSec = Math.floor(diffMs / 1000);
+  const diffMin = Math.floor(diffSec / 60);
+  const diffHour = Math.floor(diffMin / 60);
+  const diffDay = Math.floor(diffHour / 24);
+
+  if (diffSec < 60) return "just now";
+  if (diffMin < 60) return `${diffMin}m ago`;
+  if (diffHour < 24) return `${diffHour}h ago`;
+  if (diffDay < 30) return `${diffDay}d ago`;
+  return formatDate(d);
+}
+// #endregion formatRelativeTime:Function
+
+// #region formatFileSize:Function [TYPE Function]
+// @BRIEF Format bytes to human-readable size (e.g. "1.5 MB").
+export function formatFileSize(bytes: number | null | undefined): string {
+  if (bytes == null || bytes < 0) return "";
+  if (bytes === 0) return "0 B";
+  const units = ["B", "KB", "MB", "GB", "TB"];
+  const i = Math.floor(Math.log(bytes) / Math.log(1024));
+  const val = bytes / Math.pow(1024, i);
+  return `${val.toFixed(i === 0 ? 0 : 1)} ${units[i]}`;
+}
+// #endregion formatFileSize:Function
+
+// #endregion Utils.DateFormat