chore: genericize plugin manifests for public release

main is now the shareable artifact: placeholder host and clientId, no
instance-specific hostnames, marketplace renamed to cybercove-labs.

The filled-in manifest for the live instance lives on branch
instance/dnspegasus and is installed with a #ref fragment, which
`claude plugin marketplace add` honors and persists even though it is
absent from --help (verified on Claude Code 2.1.220).

README: plugin install is now path A, documenting both the fork-and-edit
and the #ref branch approaches; remaining paths renumbered B/C/D.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -1,16 +1,16 @@
 {
   "$schema": "https://anthropic.com/claude-code/marketplace.schema.json",
-  "name": "dnspegasus",
-  "description": "Self-hosted Claude Code plugins for the dnspegasus.net infrastructure.",
+  "name": "cybercove-labs",
+  "description": "Open-source Claude Code plugins released by CyberCove Labs.",
   "owner": {
-    "name": "jknapp",
-    "url": "https://repo.anhonesthost.net/jknapp/shared-memory"
+    "name": "CyberCove Labs",
+    "url": "https://repo.anhonesthost.net/cybercove-labs/shared-memory"
   },
   "plugins": [
     {
       "name": "shared-memory",
       "source": "./plugin",
-      "description": "Shared persistent memory and snippet library for Claude Code sessions, backed by memory.dnspegasus.net and authenticated with Authentik OIDC."
+      "description": "Shared persistent memory and snippet library for Claude Code sessions, backed by your own shared-memory server and authenticated with OIDC."
     }
   ]
 }