Add cwc-makers plugin: /maker-setup Cardputer onboarding (#1730)

* Add cwc-makers plugin: /keep-thinking Cardputer onboarding

Packages the Code-with-Claude Makers (claude.com/cwc-makers) Cardputer
experience as a one-command flow for event attendees:

- commands/keep-thinking.md: user entry point — clones
  moremas/build-with-claude and runs the m5-onboard provisioning flow
- skills/m5-onboard/SKILL.md: vendored from upstream onboard/SKILL.md;
  Installation section replaced with clone-location note; explicit
  'relay physical button steps to user' directive added
- skills/cardputer-buddy/SKILL.md: post-onboarding app iteration

All three are user-invocable; /keep-thinking is the intended entry
point. Skill content is Apache-2.0 from the upstream repo.

Linear: CC-1975

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

🏠 Remote-Dev: homespace

* Rename /keep-thinking → /start-making

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

🏠 Remote-Dev: homespace

* Rename /start-making → /maker-setup

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

🏠 Remote-Dev: homespace

plugins/cwc-makers/.claude-plugin/plugin.json

@@ -0,0 +1,21 @@
+{
+  "name": "cwc-makers",
+  "version": "1.0.0",
+  "description": "Seamless onboarding for the Code-with-Claude Makers Cardputer: one /maker-setup command clones the build-with-claude repo, flashes UIFlow firmware, and installs the Claude Buddy app bundle onto a freshly-plugged-in M5Stack Cardputer-Adv.",
+  "author": {
+    "name": "Anthropic",
+    "email": "support@anthropic.com"
+  },
+  "homepage": "https://claude.com/cwc-makers",
+  "repository": "https://github.com/moremas/build-with-claude",
+  "license": "Apache-2.0",
+  "keywords": [
+    "cardputer",
+    "m5stack",
+    "esp32",
+    "hardware",
+    "maker",
+    "onboarding",
+    "cwc"
+  ]
+}