feat(cli): v0.1.7 — --name, --mesh, --join flags for launch

- `claudemesh launch --name Mou` sets per-session display name
- `claudemesh launch --mesh car-dealers` selects mesh (interactive picker if >1)
- `claudemesh launch --join <token-or-url>` joins a mesh inline before launching
- Broker stores per-presence displayName override (prefers over member default)
- Session config isolated via tmpdir (auto-cleanup on exit)

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

packages/db/migrations/0004_add-presence-display-name.sql

@@ -0,0 +1 @@
+ALTER TABLE "mesh"."presence" ADD COLUMN "display_name" text;