fix: make Timestamp component locale-aware via formatTimestamp

Timestamp was hardcoded to "es" locale. Now uses formatTimestamp()
from useLocale.ts for consistent locale-aware time formatting.
Added Timestamp to CLAUDE.md shared components documentation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -346,6 +346,7 @@ This allows `applyTheme()` to switch themes at runtime.
   - **`Label`** (`src/components/ui/label.tsx`): Dotted-border tag/badge for metadata labels (language, kind, status, metric type). Two sizes: `sm` (default) and `md`. Use instead of ad-hoc `<span>` tags for tag-like indicators.
   - **`RichText`** (`src/components/nostr/RichText.tsx`): Universal Nostr content renderer. Parses mentions, hashtags, custom emoji, media embeds, and nostr: references. Use for any event body text — never render `event.content` as a raw string.
   - **`CustomEmoji`** (`src/components/nostr/CustomEmoji.tsx`): Renders NIP-30 custom emoji images inline. Shows shortcode tooltip, handles load errors gracefully.
+  - **`Timestamp`** (`src/components/Timestamp.tsx`): Locale-aware short time display (e.g., "2:30 PM" or "14:30"). Takes a Unix timestamp in seconds. Use for inline time rendering in chat messages, lists, and log entries. For other formats (relative, date, datetime), use `formatTimestamp()` from `src/hooks/useLocale.ts`.
 
 ## Important Patterns
 

src/components/Timestamp.tsx

@@ -1,11 +1,5 @@
-import { useMemo } from "react";
+import { formatTimestamp } from "@/hooks/useLocale";
 
 export default function Timestamp({ timestamp }: { timestamp: number }) {
-  const formatted = useMemo(() => {
-    const intl = new Intl.DateTimeFormat("es", {
-      timeStyle: "short",
-    });
-    return intl.format(timestamp * 1000);
-  }, [timestamp]);
-  return formatted;
+  return formatTimestamp(timestamp, "time");
 }