Add CHANGELOG for 1.8.8

[philippjfr]

Panel 1.8.8 focuses on stability, event handling correctness, Pyodide improvements, ESM robustness, and multiple UI fixes. It also introduces a new experimental freeze option for hold() to improve performance during batch updates. Many thanks to the contributors to this release including:
@philippjfr, @sumaiyaislam, @emunsing, @AtharvaJaiswal005, @DevilSpecial, @danielalanbates, @florianverdonck, @ahuang11, @SimonHeybrock, @Coderambling, and @MarcSkovMadsen.

✨ Enhancements

• Allow list handling improvements (#8405)
• Add additional safety guards to custom models (#8410)
• Experimental freeze support in hold()
  Add a freeze=True option to defer expensive Bokeh model graph recomputation until the hold context exits. This can significantly improve performance when batch-updating many models.
  (Marked experimental.) (#8417)
• Add missing Callback.unwatch() method with tests (#8453)
• Ensure ESM model definitions can be loaded dynamically (#8432)
• Improve widget.link() to properly support HoloViews streams (#8450)

🐛 Bug Fixes

• Ensure ReactComponent children render even when view initialization is slow (#8406)
• Fix CDN resolution issues in server mode for loading.css and es-module-shims (#8408)
• Fix LaTeX rendering in Markdown pane under Pyodide (#8424)
• Fix resource resolution when pathname changes (#8433)
• Ensure only param value events are deduplicated (#8436)
• Fix OAuth user data being overwritten during updates (#8447)
• Fix pipeline "Next" button disabled state when navigating back (#8443)
• Fix Video pane rejecting URLs with query parameters (#8440)
• Fix Number and String indicators defaulting to black in dark theme (#8441)
• Ensure embedding works correctly with .from_param() (#8445)

📦 Dependency Updates

• Bump pyodide to 0.29.3 (#8446)

📚 Documentation

• Update ChatFeed OpenAI examples to SDK v1.0+ format (#8426)
• Documentation link updates (croniter README) (#8401)

🧪 Tests & Maintenance

• Use direct html.escape import for clarity (#8409)
• Add tests for Button on_click parameter (#8435)

[SuMayaBee]

Thank you so much for the mention! I'm really grateful to be a part of the Panel 1.8.8 release and to contribute alongside everyone. Just a small correction, my actual GitHub handle is @SuMayaBee rather than @sumaiyaislam. My real name is Sumaiya Islam, so the mix-up makes perfect sense! It's all good. 😊

I'm excited to keep contributing and helping out where I can. Thanks again for all the hard work on getting this release out. 🚀 🙌

[hoxbro]

Should be corrected with #8458

[danielalanbates]

Thank you for the review! Glad it helps. 🙏