feat(cli): use Claude Code session ID for mesh peer identity

claudemesh launch now generates a UUID and passes it to claude via
--session-id flag + CLAUDEMESH_SESSION_ID env var. The MCP server
reads this and sends it in the hello handshake.

Fallback: when launched without claudemesh launch (e.g., claude --resume),
detectClaudeSessionId() scans ~/.claude/projects/ for the most recent
.jsonl file and extracts the session UUID from the filename.

Benefits:
- Broker detects reconnections (same session = restore state)
- Multiple peers in same project dir get unique identities
- Session identity persists across --resume

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "claudemesh-cli",
-  "version": "0.8.1",
+  "version": "0.8.2",
   "description": "Claude Code MCP client for claudemesh — peer mesh messaging between Claude sessions.",
   "keywords": [
     "claude-code",