rebrand: sweep remaining switchboard refs + rename cookies/storage keys

- CSS headers (4 files): Switchboard Core → Armature
- Editor .mjs headers (8 files): Chat Switchboard → Armature
- SQL migration comments + seed data (20 files): Switchboard Core → Armature
- Webhook header: X-Switchboard-Event → X-Armature-Event
- Cookie: sb_token → arm_token (3 Go files + auth.js)
- localStorage: sb_auth → arm_auth (auth.js + 2 test runners)
- localStorage: switchboard_theme → armature_theme (theme.js + base.html)
- Debug engine filter: chatSwitchboard/switchboard/sb_ → armatureChat/armature/arm_
- JS export: switchboardTheme → armatureTheme (theme.mjs + code-editor.mjs)

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

packages/icd-test-runner/js/framework.js

@@ -270,7 +270,7 @@
 
   function getAuthTokenFromStorage() {
     var env = (T.base || '').replace(/^\//, '') || 'default';
-    var keys = ['sb_auth_' + env, 'sb_auth', 'sb_token'];
+    var keys = ['arm_auth_' + env, 'arm_auth', 'arm_token'];
     for (var i = 0; i < keys.length; i++) {
       try {
         var raw = localStorage.getItem(keys[i]);