Fix reply pagination after preloading

[ruibaby]

What this PR does

• Restore withReplySize as the initial reply preload size and clamp it to the configured reply page size
• Reconcile a partially preloaded first page before loading subsequent pages
• Load page two immediately when the initial preload already contains a full first page
• Prevent duplicate load requests and only advance pagination after a successful response
• Add reply size constraints and focused pagination regression tests

Reproduction

1. Enable preloading replies with comments.
2. Set the reply page size and initial preload size to the same value.
3. Open a comment with more replies than the configured size and click Load more.

Before this change, the first click fetched page one again and displayed no new replies. After this change, the first click appends page two.

Testing

• pnpm -C packages/comment-widget test
• pnpm build
• ./gradlew check

Fixes #122

修复回复分页条数与同时加载回复条数相同时，首次点击“加载更多”无法加载新回复的问题。

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: ce33f16dd0

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Clamp zero-sized legacy configurations before fetching

Existing installations can have replySize: 0 because the previous settings schema only required a value and imposed no minimum. Unlike the former || 10 fallback, ?? 10 preserves that zero, so this path sends size=0 to the reply endpoint; the same unnormalized value is also passed to getNextReplyRequest, breaking subsequent pagination. The new form constraint does not migrate saved settings, so normalize the configured page size to a positive fallback before using it.

Useful? React with 👍 / 👎.