Grouped emoji reactions, npub search, notification fix, dev logger

- Emoji reactions now display as grouped pills (❤️5 🤙3 🔥2) instead
  of a single aggregated count. Multi-reaction per note supported.
- Throttled reaction fetch queue (max 4 concurrent) prevents relay overload.
- Searching a bare npub/nprofile navigates directly to that profile.
- Notification poller waits for relay connection before first fetch,
  fixing empty results on startup.
- Dev-only debug logger (src/lib/debug.ts) — silent in production builds.

src/lib/debug.ts

@@ -0,0 +1,8 @@
+/** Dev-only logger — all output is stripped in production builds. */
+const isDev = import.meta.env.DEV;
+
+export const debug = {
+  log: (...args: unknown[]) => { if (isDev) console.log("[Wrystr]", ...args); },
+  warn: (...args: unknown[]) => { if (isDev) console.warn("[Wrystr]", ...args); },
+  error: (...args: unknown[]) => { if (isDev) console.error("[Wrystr]", ...args); },
+};