feat: add Ollama proxy timeouts, SSH key migration, polish skills, and demo content

- Update all skill SSH commands from sshpass to key-based auth (~/.ssh/archipelago-deploy)
- Add proxy_connect_timeout 120s to nginx Ollama location blocks
- Add new polish/sweep skills for overnight automation
- Add demo content (documents, photos) for demo stack
- Add .ssh/ to .gitignore

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

demo/content/photos/node-rack-setup.svg

@@ -0,0 +1,11 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="1200" height="800" viewBox="0 0 1200 800">
+  <defs>
+    <linearGradient id="bg" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#1a1a2e;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#16213e;stop-opacity:1" />
+    </linearGradient>
+  </defs>
+  <rect width="1200" height="800" fill="url(#bg)"/>
+  <text x="600" y="380" text-anchor="middle" font-family="Arial" font-size="32" fill="rgba(255,255,255,0.6)">node-rack-setup</text>
+  <text x="600" y="430" text-anchor="middle" font-family="Arial" font-size="16" fill="rgba(255,255,255,0.3)">Demo Photo Placeholder</text>
+</svg>