Save in-progress keysat integration and StartOS 0.4 work

Snapshot of the working tree before cleanup. Captures:
- Keysat licensing: server/license.js, /api/license/* endpoints in
  server/index.js, activation modal in public/index.html, embedded
  Ed25519 issuer key (assets/issuer.pub).
- StartOS 0.4 expansion: setApiKey action, version files v0.1.1
  through v0.1.15, file-models/config.json.ts, manifest updates.
- Self-hosted registry server (startos-registry/).
- Build/deploy scripts (bin/bump-version.sh, bin/deploy.sh, vendored
  yt-dlp binary), .gitignore, .deploy.env.example.
- Recent design docs (KEYSAT_INTEGRATION.md, UPGRADE-DESIGN.md) —
  retained here so they remain recoverable when removed in the
  follow-up cleanup commit.

startos-registry/packages/youtube-summarizer/INSTRUCTIONS.md

@@ -0,0 +1,23 @@
+# YouTube Summarizer
+
+## Getting Started
+
+1. After installing, go to the service menu and run the **Set Gemini API Key** action
+2. Get a free API key at [aistudio.google.com/apikey](https://aistudio.google.com/apikey)
+3. Open the YouTube Summarizer web interface from the service's Interfaces section
+4. Paste any YouTube URL to download, transcribe, and summarize
+
+## Features
+
+- Download and transcribe YouTube videos and podcast episodes
+- AI-powered topic-by-topic summaries with timestamps
+- Channel and podcast feed subscriptions with auto-detection of new episodes
+- Background processing queue
+- Organized history with folders
+- Responsive web interface
+
+## Notes
+
+- The embedded YouTube player will not work if you are connected to a VPN
+- Processing time depends on video length and your Gemini API tier
+- Free Gemini API tier has rate limits; consider upgrading for heavy use