classify recommended feeds by signal strength

Annotate the "What to read next" section with per-link signal-strength emojis and add a short legend that defines low/medium/high feed volume expectations.

This updates the recommended resources list to make scan-time decisions easier for readers who want to control the volume of ongoing content they subscribe to. It also incorporates the final manual curation of links and tiers in that section.

Manual testing:
- Run bun lint
- Confirm prettier reports no further edits
- Confirm astro check returns 0 errors

Special considerations:
- Existing Astro warning about duplicate content id in expanding-horizons remains unchanged and is unrelated to this update.

fix #3

Author: mkaput

src/content/docs/expanding-horizons.md

@@ -84,23 +84,32 @@ So to answer the question: when should you use MCP, a skill, or a CLI? If possib
 
 If you want to stay sharp in agentic engineering, subscribe to these recommended feeds:
 
+Signal strength: 🟢 Low (~1 post/week), 🟡 Medium (~2-3 posts/week), 🔴 High (daily or high-volume feeds).
+
 ### Independent voices
 
-- [Simon Willison's Blog](https://simonwillison.net/)
-- [Thorsten Ball's Joy & Curiosity Newsletter](https://registerspill.thorstenball.com/)
-- [Armin Ronacher's Blog](https://lucumr.pocoo.org/)
-- [Mitchell Hashimoto's Blog](https://mitchellh.com/)
+- 🔴 [Simon Willison's Blog](https://simonwillison.net/)
+- 🟢 [Thorsten Ball's Joy & Curiosity Newsletter](https://registerspill.thorstenball.com/)
+- 🟢 [Armin Ronacher's Blog](https://lucumr.pocoo.org/)
+- 🟢 [Mitchell Hashimoto's Blog](https://mitchellh.com/)
+- 🔴 [Andrej Karpathy on X](https://x.com/karpathy)
 
-### Anthropic devs
+### Harness Developers
 
-- [Boris Cherny](https://x.com/bcherny)
-- [Lance Martin](https://x.com/RLanceMartin)
+- 🔴 [Boris Cherny on X](https://x.com/bcherny) (Anthropic)
+- 🔴 [Lance Martin on X](https://x.com/RLanceMartin) (Anthropic)
+- 🔴 [Thariq Shihipar on X](https://x.com/trq212) (Anthropic)
+- 🔴 [Thibault Sottiaux on X](https://x.com/thsottiaux) (OpenAI)
+- 🔴 [Alexander Embiricos on X](https://x.com/embirico) (OpenAI)
+- 🔴 [Thorsten Ball on X](https://x.com/thorstenball) (Amp)
+- 🔴 [OpenCode on X](https://x.com/opencode) (they retweet all their devs)
 
 ### Product and engineering blogs
 
-- [OpenAI Engineering News](https://openai.com/news/engineering/)
-- [Claude Code Blog](https://claude.com/blog/category/claude-code)
-- [Cursor Blog](https://cursor.com/blog)
-- [Amp News](https://ampcode.com/news)
+- 🟡 [OpenAI Engineering News](https://openai.com/news/engineering/)
+- 🟡 [Claude Code Blog](https://claude.com/blog/category/claude-code)
+- 🟡 [Cursor Blog](https://cursor.com/blog)
+- 🟡 [Google Gemini on X](https://x.com/GeminiApp)
+- 🟢 [Amp News](https://ampcode.com/news)
 
 ---