fix(rename): split 404 vs 403 + surface API error body (v1.19.2)

The rename route was collapsing "mesh doesn't exist" and "exists
but you don't own it" into a single 404 with body
{"error":"mesh not found or you are not the owner"}, and the CLI
was throwing that body away — the user only saw "API error 404:
Not Found", which is actively misleading when they have multiple
accounts and signed in to the wrong one.

Server: separate lookup-then-update. 404 only when the slug is
missing; 403 with an actionable message when the caller is not
the owner.

CLI: parse the {error} body off ApiError and print it instead of
the bare statusText. Map status codes to specific exit codes
(401 -> AUTH_FAILED, 403 -> PERMISSION_DENIED, 404 -> NOT_FOUND).

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

apps/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "claudemesh-cli",
-  "version": "1.19.1",
+  "version": "1.19.2",
   "description": "Peer mesh for Claude Code sessions — CLI + MCP server.",
   "keywords": [
     "claude-code",