[feature] Accounts area navigation and filtering: card filter/search, company sorting and pinning, ⌘K, remembered collapse state

[Lanznx]

Once you have a lot of cards, the area is unusable without filtering, search, and quick navigation (acceptance bar: 40+ cards, real transcripts).

Scope

1. Card filtering and search (B-2): filter by person, thread, and confidence; full-text search across claims.
2. Company list sorting (B-6): currently sorted by creation time; switch to sorting by most recent activity, plus the ability to pin to top.
3. ⌘K quick switcher (B-7): jump quickly to a company, person, or thread; keyboard navigation (j/k to move between cards, e to edit).
4. Remembered collapse state for groups (B-10): category groups currently expand again every time you re-enter — the state should be remembered. A two-column density option for the grouping is worth considering.

Notes

• The remembered collapse state can reuse the localStorage pattern already used by react-resizable-panels
• Search must match claim text, quotes, and person/company names (including aliases)