Improve rendering performance and replace verse-change fade with smooth scroll

[alex-rawlings-yyc]

• Memoize SegmentView, TokenChip, and a new FocusablePhrase wrapper in ContinuousView so that verse clicks and phrase-focus changes only re-render the two affected components rather than the entire chapter or token strip
• Replace inline onClick callbacks on SegmentView with a stable handleSegmentSelect useCallback and a typed onSelect prop, which allows memo to skip unchanged segments
• Remove the 500 ms opacity fade that delayed verse jumps in ContinuousView; use scrollIntoView({ behavior: 'smooth' }) instead so the strip scrolls directly to the new verse without a perceptible pause

---

This change is 

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: f5a96676-285d-4eac-9aa4-21715a7f1782

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch continuous-scroll-memoizations

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[imnasnainaec]

@imnasnainaec partially reviewed 8 files and made 1 comment.
Reviewable status: 4 of 9 files reviewed, 1 unresolved discussion (waiting on alex-rawlings-yyc).

---

src/components/ContinuousView.tsx line 0 at r1 (raw file):
@alex-rawlings-yyc The fade-out and fade-in was a request from Jason that I agree with. When the ContinuousView receives an external reference change, it's quite jarring to have it scroll so far.

[alex-rawlings-yyc]

src/components/ContinuousView.tsx line at r1 (raw file):

Previously, imnasnainaec (D. Ror.) wrote…

@alex-rawlings-yyc The fade-out and fade-in was a request from Jason that I agree with. When the ContinuousView receives an external reference change, it's quite jarring to have it scroll so far.

Done.

[alex-rawlings-yyc]

I'm going to strip away the scrolling and see if this PR actually does anything meaningful