Covers all bugs fixed in the DOM-preserving hydration work:
DOM preservation:
- Islands hydrate without errors or warnings
- Both islands report hydrated in boot log
- No replaceChildren called on island elements
- No stray comment markers in island DOM
Counter text nodes (was: "0 / 16" → "0"):
- Counter shows full "0 / 16" text
- Counter has exactly 3 text nodes (value, separator, total)
- Counter updates on forward/back clicks
Event listeners (was: buttons had no click handlers):
- Stepper buttons respond to clicks
- Header navigation links present after hydration
Code view:
- Syntax-highlighted spans present after hydration
- Code highlighting advances with stepper clicks
SSR DOM identity:
- Element count roughly preserved (not doubled)
- Stepper buttons are the SAME DOM nodes (JS property survives)
- Header elements are the SAME DOM nodes
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>