feat(workspace): claudemesh me notifications + dashboard parity

ships v0.4.0 phase 3.

api: GET /v1/me/notifications aggregates the mesh.notification
table across every joined mesh in a 7-day window (?since=iso
overrides, ?include=all surfaces already-read). returns sender +
topic + mesh context plus a 240-char snippet for v1 plaintext
messages or raw ciphertext for v2 (the dashboard topic-key cache
decrypts client-side).

cli (1.12.0): claudemesh me notifications — terse unread feed
with @ dot, --all to include read, --since for custom window.

web: /dashboard/notifications mirrors the cli view in card form,
adds a notifications entry to the dashboard sidebar between
topics and invites. each card links straight to the topic chat.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "claudemesh-cli",
-  "version": "1.11.0",
+  "version": "1.12.0",
   "description": "Peer mesh for Claude Code sessions — CLI + MCP server.",
   "keywords": [
     "claude-code",