fix(core): RTL arrow-key nav for TreeList + auto-detect direction across focus hooks

[nynexman4464]

What

Two related RTL keyboard-navigation improvements to the focus hooks:

1. TreeList now navigates correctly in RTL. useTreeFocus mirrors ArrowLeft/ArrowRight under dir="rtl" — ArrowLeft expands / enters children, ArrowRight collapses / moves to parent (per the WAI-ARIA Tree View pattern). Direction is auto-detected from the tree container; LTR is unchanged.

2. Deprecate the isRtl override on useListFocus / useGridFocus. All three focus hooks now auto-detect direction from the container's computed direction, so an explicit isRtl boolean is redundant — there's no valid reason to force RTL arrows in an LTR context. isRtl is marked @deprecated and slated for removal in an upcoming major (mirrors the Dialog position deprecation approach). useTreeFocus ships auto-detect only (no isRtl — it's new API).

AvatarGroup (the only component that passed isRtl explicitly) is migrated to rely on auto-detect; it previously reimplemented the same getComputedStyle(...).direction read the hook now does internally.

Why

The physical→logical CSS migration and the visual pr-rtl audit cover geometry, not keyboard semantics. useTreeFocus was the one directional-keyboard hook that hadn't been made RTL-aware, so RTL users got inverted expand/collapse. Consolidating on auto-detect (and retiring the override) keeps the public API minimal and direction handling consistent across the focus hooks.

Testing

101 tests pass across useTreeFocus / useListFocus / useGridFocus / AvatarGroup / doc-props. New RTL tests cover tree expand-on-ArrowLeft, collapse-on-ArrowRight, and vertical-keys-unaffected. Lint clean at error. LTR behavior unchanged.
@nynexman4464

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Project	Deployment	Actions	Updated (UTC)
astryx	Ready	Preview	Aug 3, 2026 4:09pm

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Modified Components

AvatarGroup _{(@astryxdesign/core)} · View in Storybook

Metric	Before	After	Delta
Bundle Size (ESM)	N/A	N/A	N/A
Lines of Code	N/A	261	-
Complexity	N/A	Medium (15)	-

Bundle Size Summary

Package	Size (ESM)	Size (CJS)	Gzipped
@astryxdesign/core	N/A	4.9KB	1.3KB

Accessibility Audit

Status: No accessibility violations detected.

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