feat: support geospatial results on the kernel path

[cathleeny]

Summary

• add WithEnableGeoSpatialSupport and the enableGeoSpatialSupport DSN parameter
• default to enabled: return EWKB through database/sql while preserving the canonical {srid,wkb} Arrow struct through GetArrowBatches
• return WKT / EWKT strings when disabled
• pass the value through the typed kernel C ABI only; it is never forwarded to SEA

Dependency

Depends on databricks/databricks-sql-kernel#361.

Validation

• uncached full go test -tags databricks_kernel ./... against the exact kernel Rustls archive: passed
• generated C header exactly matches kernel
• live Reyden E2E against the exact archive: default-enabled, explicit-enabled, and disabled-string modes passed, including logical type metadata, WKB equality, and nulls

[peco-review-bot]

✅ No issues identified by the review bot.

[peco-review-bot]

✅ No issues identified by the review bot.

[peco-review-bot]

Verdict: 1 Low

Looks solid — the EWKB conversion, struct-shape validation, pointer-based default/explicit config, and representation-aware column metadata are all correct and well-covered by tests. One low-severity note: the enableGeoSpatialSupport DSN carrier allocates KernelExperimental for both true and false, so an enableGeoSpatialSupport=... DSN on a Thrift connection is rejected at connect — diverging from the deliberate tokenCache=false no-op precedent in the same function, and untested.

[peco-review-bot]

✅ No issues identified by the review bot.

[aakash-saravanan-db]

As part of adopting the declared kernel #361 dependency, could we update both KERNEL_REV and the published kernel-bindings module versions together?

The current Linux AMD64 v1.1.0 archive lacks the new geospatial setter. Please also validate a consumer build without local archive overrides, since the source-built smoke test does not exercise that distribution path.

[peco-review-bot]

Verdict: 1 Low

Looks good — a clean, well-tested feature with solid EWKB conversion, consistent config plumbing, and thorough unit + e2e coverage. One low-severity defensive note on a panic in the per-row scan path; nothing blocking.

[peco-review-bot]

Verdict: 1 Low

Looks good — clean, well-tested geospatial feature. The EWKB rewriter (byte-order, SRID placement, dimension flags, child-type validation, bounds checks), config/DSN plumbing (pointer preserves explicit false through DeepCopy and the kernel build), and the type-reporting/value-scanning lockstep are all correct. One low-severity note on an unreachable fallback branch in ColumnTypeInfoForField; no blocking issues.

[aakash-saravanan-db]

LGTM. No further functional concerns from the review. As discussed, merge kernel #361 first, then update both KERNEL_REV and the published kernel-bindings module versions and rerun verification against those artifacts before merging this PR, including a consumer build without local archive overrides.