feat(vtable): auto-merge rectangular body multi-ranges

[Rui-Sun]

🤔 This is a ...

• New feature
• TypeScript definition update
• Test Case

🔗 Related issue link

None.

💡 Background and solution

Add opt-in select.autoMergeRanges (default false) to merge adjacent or overlapping ordinary body selections when their connected union fills a rectangle. L-shaped, holed and disconnected selections retain their separate ranges. Header, row-series and frozen-partition selections are excluded.

selectCells evaluates the complete batch after per-range normalization and deduplication, including when the final input range is a duplicate. Ctrl selection and drag selection use the same merge routine. Selection borders and selected_cell payloads reflect the final ranges.

const table = new ListTable({
  // ...existing options
  select: { autoMergeRanges: true }
});

📝 Changelog

Language	Changelog
English	Add optional rectangular multi-range auto-merge for body selections; existing behavior remains the default.
Chinese	新增可选的 body 多选区矩形自动合并能力，默认选择行为不变。

Validation

Regression coverage includes disabled behavior, adjacent/overlapping rectangles, L-shapes, holes, disconnected ranges, duplicate final ranges, Ctrl/event behavior, drag selection and frozen boundaries. Host validation details are recorded below. Product Electron tests must run in CI before review/merge; this remains a Draft PR.

☑️ Self-Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

🚀 Summary

copilot:summary

🔍 Walkthrough

copilot:walkthrough

Supersedes #5319 with the same implementation commit, submitted from a branch in this repository so repository CI secrets are available.

Runner validation

• Targeted Rush install and build passed; scope, diff and test-file checks passed.
• NOT RUN: product Jest/Electron tests; this runner has no xvfb-run/headless display.
• Draft only: run the added tests and full product suite in CI before review/merge.

Upstream CI verification

• Unit test CI: passed.
• Bug Server CI: running; the repository-secret validation outcome is not yet confirmed.