perf: trim zctl listview instead of full rebuild

[mhk197]

When exporting a ListViewArray to an Arrow list-view, the rebuild gate now branches on whether the array is already zero-copy-to-list:

• Zero-copy-to-list arrays have no overlaps and no interior gaps, so their only waste is leading/trailing unreferenced elements. These are reclaimed with a cheap trim_elements rebuild (a lazy elements slice plus an O(num_lists) offset adjustment, no element data copy), gated on the unreferenced fraction exceeding DEFAULT_TRIM_ELEMENTS_THRESHOLD.
• Non-zero-copy arrays keep the existing density-based MakeZeroCopyToList full rebuild, since they may contain overlaps, gaps, or garbage that only a full rebuild can reclaim.

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 1 improved benchmark
❌ 1 regressed benchmark
✅ 1273 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	chunked_varbinview_opt_canonical_into[(1000, 10)]	188.1 µs	225 µs	-16.41%
⚡	Simulation	chunked_varbinview_canonical_into[(100, 100)]	307.9 µs	273.1 µs	+12.74%

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 mk/listview-export-try-trim (e24a014) with develop (23ebab1)}