fix(platform): recover legal-hold matters reads without losing focus

[yannickmonney]

A failed Legal Hold Matters read now uses the existing localized DataTable failure state and retry. Retrying moves focus to the named Matters section before the read starts, so removing the retry control keeps a useful focus destination. The shared focus handoff also preserves focus that another control acquires before its queued frame.

Rebased onto main aba03419878bc46d4ec7ab7cf01d116a9e74b462; original query, filters, dialogs and localized labels remain. The recovery-hook generic changes types only. Coverage is recorded in the existing manual register.

Validation: 106 distinct selected tests pass, with an independent 16-case subset on the exact head. The final original-source overlays fail five host focus cases and three shared frame-ownership cases while their controls pass. Full platform/UI types and configured scoped lint, format, manual, conflict, SAST and commit checks pass. Whole Knip still reports seven inherited main findings; no whole-repository green claim.

Chromium with the real component, query hooks and adapters plus synthetic HTTP answers reproduces original BODY focus loss, repaired section focus, background recovery and foreign-focus preservation. EN/DE/FR desktop and narrow layouts were observed. The hidden preview cannot prove foreground focus paint; assistive technology and a live authenticated backend remain unobserved. All seven native required checks and merge-group integration remain mandatory.

Closes #3836
Closes #3837
Closes #3838

Current-main rebase

Replayed the previously accepted source fa6db96202e376d07a95e4046176075c4f0298e3 onto main d1373d84cd56972501403f62145ec52e6f65d44a, including the merged shared CI repair in #4625. The accepted feature payload and all current-main changes are preserved in one atomic commit. Configured commit and conflict checks pass; earlier behavioral proof remains recorded above. All seven native required checks and full merge-group validation remain required for this new source.

Maintenance replay: preserves the accepted feature payload on current main 7d178ca. Includes the merged #4649 Knip cleanup and the exact independently accepted one-line shared CLI inventory repair from #4654 (252f0df), which is still pending native merge on main. The fixed suite inventory keeps its discovery and source/compiled phase guards. Existing feature proof is retained; no fresh full-feature/full-workspace test or hosted-green claim. Native required checks remain mandatory.