feat[vortex-array]: add unified DisplayTreeNode for tree display and JSON serialization

[joseph-isaacs]

Introduces a unified tree model for displaying hierarchical data structures:

• Add DisplayTreeNode, Attr, AttrValue types in vortex-array/src/display/tree_model.rs
• Add TreeDisplayable trait for lazy tree rendering
• Add TreeDisplayOptions to control which attributes are included
• Update DisplayLayoutTree in vortex-layout to:
  • Support lazy text display (via Display trait)
  • Support eager JSON serialization (via to_tree_node())
  • Use configurable options for attribute filtering
• Add indexmap dependency for ordered children in JSON output

This provides a foundation for supporting both text and JSON output
without maintaining two separate code paths.

Signed-off-by: Claude noreply@anthropic.com

[codspeed-hq]

CodSpeed Performance Report

Merging this PR will degrade performance by 40.82%

_{Comparing claude/unify-display-json-0G4Ng (03daae6) with develop (13f120f)}

⚠️ 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.

Summary

⚡ 3 improved benchmarks
❌ 8 regressed benchmarks
✅ 1251 untouched benchmarks
⏩ 1290 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	u16_FoR[10M]	6.2 µs	10.4 µs	-40.82%
⚡	WallTime	u8_FoR[10M]	71.7 µs	5.8 µs	×12
❌	Simulation	canonical_into_non_nullable[(10000, 100, 0.01)]	2.1 ms	2.9 ms	-27.41%
❌	Simulation	canonical_into_non_nullable[(10000, 100, 0.0)]	1.9 ms	2.7 ms	-29.75%
❌	Simulation	canonical_into_non_nullable[(10000, 100, 0.1)]	3.7 ms	4.5 ms	-18.17%
⚡	Simulation	canonical_into_nullable[(10000, 10, 0.0)]	528.5 µs	444.3 µs	+18.96%
⚡	Simulation	canonical_into_nullable[(10000, 100, 0.0)]	4.9 ms	4.1 ms	+19.65%
❌	Simulation	into_canonical_non_nullable[(10000, 100, 0.01)]	2.2 ms	3 ms	-27.07%
❌	Simulation	into_canonical_non_nullable[(10000, 100, 0.0)]	1.9 ms	2.7 ms	-29.42%
❌	Simulation	into_canonical_nullable[(10000, 100, 0.0)]	4.4 ms	5.2 ms	-15.75%
❌	Simulation	into_canonical_non_nullable[(10000, 100, 0.1)]	3.8 ms	4.6 ms	-17.72%

Footnotes

1. 1290 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. ↩