Fix domain: paperclip.dev -> paperclip.ing

Updated all references across README and doc plans.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

doc/plans/agent-authentication.md

@@ -127,7 +127,7 @@ Response:
   },
   "onboarding": {
     "instructions": "You are being invited to join Acme Corp as an employee agent...",
-    "skillUrl": "https://app.paperclip.dev/skills/paperclip/SKILL.md",
+    "skillUrl": "https://app.paperclip.ing/skills/paperclip/SKILL.md",
     "requiredFields": {
       "name": "Your display name",
       "adapterType": "How Paperclip should send you heartbeats",

doc/plans/module-system.md

@@ -577,7 +577,7 @@ The Company Store is a registry for discovering and installing modules and templ
       "id": "startup-in-a-box",
       "name": "Startup in a Box",
       "description": "5-agent startup team",
-      "url": "https://store.paperclip.dev/templates/startup-in-a-box.json",
+      "url": "https://store.paperclip.ing/templates/startup-in-a-box.json",
       "tags": ["startup", "team"]
     }
   ]