feat: push zonemap ranges into fragment scans

[majin1102]

Summary

• plan physical row ranges from zonemap statistics on the driver
• attach merged FragmentSlice ranges to single-fragment Lance splits
• pass slices through both ordinary columnar scans and pushed COUNT(*) scans
• conservatively fall back to full-fragment scans for unsupported predicates, incomplete coverage, or invalid metadata
• preserve snapshot isolation by planning zonemap ranges and fragments from the same opened dataset version
• disable fragment row-count limit pruning when a split carries physical slices

Validation

• ./mvnw -Dmaven.repo.local=/tmp/lance-fragment-slice-m2 spotless:check
• ./mvnw -Dmaven.repo.local=/tmp/lance-fragment-slice-m2 compile -pl lance-spark-3.5_2.13 -am
• ./mvnw -Dmaven.repo.local=/tmp/lance-fragment-slice-m2 test -pl lance-spark-3.5_2.13 -am
  • 1401 tests, 0 failures, 0 errors
• focused FragmentSlice planner tests, including multi-fragment and multi-slice planning
  • 11 tests, 0 failures

Dependency / draft status

Depends on lance-format/lance#8951 for the Java/JNI FragmentSlice scanner API.

The branch currently targets lance-core:12.0.0-beta.11, built locally from that PR into an isolated Maven repository. Keep this PR as draft until the Lance change is merged and a public artifact is available; then replace the dependency version in a follow-up commit.

Scope

This PR only implements ZoneMap to FragmentSlice scan pruning. It does not introduce distributed BTree/FTS index planning, index scan tasks, or plan_splits.