feat: append data with reserved stable row ids

[majin1102]

Close #6466

What this PR does

This PR introduces a new ReserveRowIds transaction operation and extends Append with an optional row_ids field. Both changes affect transaction metadata and the serialized transaction schema, so this part needs a vote.

What this PR does not do

This PR does not add any new field or persisted state to the manifest. The manifest format remains unchanged. The only manifest-related effect is that this PR provides a controlled transaction-level entry point for reserving and consuming next_row_id, rather than changing manifest contents themselves.

[github-actions]

ACTION NEEDED
Lance follows the Conventional Commits specification for release automation.

The PR title and description are used as the merge commit message. Please update your PR title and description to match the specification.

For details on the error please inspect the "PR Title Check" action.

[codecov]

Codecov Report

❌ Patch coverage is 69.33638% with 134 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
rust/lance/src/dataset/transaction.rs	50.31%	65 Missing and 13 partials ⚠️
rust/lance/src/dataset/write/commit.rs	67.34%	12 Missing and 4 partials ⚠️
rust/lance/src/io/commit/conflict_resolver.rs	65.90%	13 Missing and 2 partials ⚠️
rust/lance/src/dataset/write/insert.rs	59.25%	10 Missing and 1 partial ⚠️
rust/lance-table/src/format/manifest.rs	50.00%	6 Missing ⚠️
rust/lance/src/dataset.rs	66.66%	4 Missing and 2 partials ⚠️
rust/lance/src/dataset/rowids.rs	98.40%	0 Missing and 2 partials ⚠️

📢 Thoughts on this report? Let us know!

[majin1102]

@jackye1995 Hi, could you take a look at this issue and PR? If the motivation and proposal make sense to you, I’ll start a vote thread.