fix(native): lower version gate after Rust incremental purge is complete

[carlos-alm]

Context

PR #865 fixes several native engine bugs (scoped deletion, barrel resolution, SQL purge order) but the Rust incremental purge still produces doubled node counts when the native orchestrator runs:

• incremental-edge-parity: 22 nodes vs expected 11
• incremental-parity: 6 dataflow edges vs expected 3
• scoped-rebuild: deleted file nodes not purged (2 vs 0)

The version gate in shouldSkipNativeOrchestrator (pipeline.ts:274) deliberately uses <= 0 to keep 3.9.0 on the JS pipeline.

Action

Once the Rust purge_changed_files correctly removes old nodes before re-insert:

1. Change semverCompare(ctx.engineVersion, '3.9.0') <= 0 to < 0 (or bump the gate version)
2. Verify all three test suites pass with the native orchestrator enabled

Related

• PR fix(native): correct incremental purge, scoped deletion, and barrel resolution #865 (initial fixes)
• Greptile review comment on pipeline.ts:274