Add plan parent-reduction rule API

[joseph-isaacs]

Summary

• add a typed PlanParentReduceRule API for child-driven physical-plan rewrites
• add a type-erased adapter for collecting heterogeneous typed rules
• add an ordered static PlanParentRuleSet whose first successful rewrite wins
• define rules as one-step rewrites while leaving recursive traversal to the optimizer
• verify in debug builds that rewrites preserve the parent row count and dtype
• expose the framework through vortex_layout::plan::optimizer

Stack

This is part 2 of the plan-native scan stack. It is based on #9142 and is followed by #9166.

Scope

This PR only introduces the rule framework and API contract. It registers no concrete rules and
does not change optimization behavior.

Checks

• cargo test -p vortex-layout
• cargo clippy -p vortex-layout --all-targets --all-features -- -D warnings
• cargo +nightly fmt --all -- --check
• git diff --check

[codspeed-hq]

Merging this PR will degrade performance by 0.46%

⚡ 4 improved benchmarks
❌ 3 regressed benchmarks
✅ 1927 untouched benchmarks
⏩ 51 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	decode_varbin[(1000, 2)]	61.5 µs	78.4 µs	-21.51%
❌	Simulation	compress_fsst[(1000, 64, 8)]	1 ms	1.2 ms	-11.67%
❌	Simulation	compress_fsst[(10000, 64, 4)]	8.6 ms	9.7 ms	-10.57%
⚡	Simulation	take[small_m/shuffled/primitive/nonnull/chunks=16384/indices=16]	1.3 ms	1.2 ms	+12.41%
⚡	Simulation	decompress[u64, (1000, 16)]	72.3 µs	64.4 µs	+12.2%
⚡	Simulation	compact_sliced[(4096, 90)]	1.9 µs	1.7 µs	+11.69%
⚡	Simulation	compact_sliced[(16384, 90)]	2 µs	1.8 µs	+10.81%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing vortex-plan-rules (825351d) with vortex-plan (c351747)²}

Footnotes

1. 51 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on vortex-plan (55e7a8c) during the generation of this report, so 31bd037 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩