feat: collapse mesh.name and mesh.slug into one identifier (v1.21.0)

Pre-launch fix: every visible surface already keyed on slug, so
"name" was a parallel string that only existed to confuse users
on rename ("I renamed but nothing visible changed").

Now slug IS the identifier. claudemesh rename <old> <new> is the
whole rename surface. PATCH /api/cli/meshes/:slug body becomes
{ slug } and the route writes both columns to keep them in sync.
Mesh create derives slug from input.name and stores name = slug.
Pickers drop the (parens). The claudemesh slug verb shipped 30
min ago is removed — merged into rename.

The mesh.name DB column stays for now to avoid touching ~25
reader sites; a follow-up migration drops it.

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

apps/cli/src/entrypoints/cli.ts

@@ -73,8 +73,7 @@ Mesh
   claudemesh launch [slug]         launch Claude Code on a mesh (alias: connect)
   claudemesh list                  show your meshes (alias: ls)
   claudemesh delete [slug]         delete a mesh (alias: rm)
-  claudemesh rename <slug> <name>  rename a mesh's display name (slug stays)
-  claudemesh slug <old> <new>      change a mesh's slug (URL-safe identifier)
+  claudemesh rename <old> <new>    change a mesh's slug (the identifier you see and type)
   claudemesh share [email]         share mesh (invite link / send email)
 
 Peer (resource form, recommended)
@@ -313,7 +312,6 @@ async function main(): Promise<void> {
     case "list": case "ls": { const { runList } = await import("~/commands/list.js"); await runList(); break; }
     case "delete": case "rm": { const { deleteMesh } = await import("~/commands/delete-mesh.js"); process.exit(await deleteMesh(positionals[0] ?? "", { yes: !!flags.y || !!flags.yes })); break; }
     case "rename": { const { rename } = await import("~/commands/rename.js"); process.exit(await rename(positionals[0] ?? "", positionals[1] ?? "")); break; }
-    case "slug": { const { slug } = await import("~/commands/slug.js"); process.exit(await slug(positionals[0] ?? "", positionals[1] ?? "")); break; }
     case "share": case "invite": { const { invite } = await import("~/commands/invite.js"); process.exit(await invite(positionals[0], { mesh: flags.mesh as string, json: !!flags.json })); break; }
     case "disconnect": { const { runDisconnect } = await import("~/commands/kick.js"); process.exit(await runDisconnect(positionals[0], { mesh: flags.mesh as string, stale: flags.stale as string, all: !!flags.all })); break; }
     case "kick": { const { runKick } = await import("~/commands/kick.js"); process.exit(await runKick(positionals[0], { mesh: flags.mesh as string, stale: flags.stale as string, all: !!flags.all })); break; }