Fix syntax highlighting in inline diffs

[levivilet]

Summary

• pass tokenized left and right lines to the inline diff renderer
• render deletion rows from left-side tokens and context/insertion rows from right-side tokens
• preserve the plain-text fallback when tokenization is unavailable

Verification

• npm test (110 suites, 322 tests)
• npm run type-check
• npm run lint
• npm run build
• integrated LVCE editor check: YAML source-control diff rendered 36 token spans with computed theme colors