fix(ui): list search input resets while typing (regression from #146 persistence)

[pskillen]

Problem

As a consequence of #146 (persist list table sort, columns, and filters in localStorage), controlled text fields — especially list name search inputs — can reset while the operator is still typing.

When the user enters or deletes text quickly, especially on a list page that triggers a large re-render (filtered DataTable, distance sort, etc.), the field value is briefly overwritten from persisted/URL state and the keystroke is lost.

Typical symptom: backspacing to clear or shorten a search string, but deleted characters immediately reappear.

Suspected root cause

List search is a fully controlled input bound to URL search params via useChannelListQuery and useListNameQuery:

• nameFilter ← searchParams.get('q')
• setNameFilter → setSearchParams on every keystroke and debouncedMerge*ListPrefs (300 ms) to localStorage

On mount / location.search change, a hydration useEffect restores prefs from localStorage when the URL has no relevant params (hasEntityListUrlParams / hasChannelListUrlParams).

Race when clearing or rapidly editing search:

1. Operator deletes the last character → q is removed from the URL.
2. Hydration effect sees no URL params and reads stale localStorage (debounced write has not flushed yet).
3. Effect calls setSearchParams with the old q value → text reappears.

Heavy list re-renders (channels table + filters) may widen the window where URL/state and the input are briefly out of sync during rapid entry.

Possible fix

Debounce the filter input at the UI boundary — keep a short-lived local draft value in the text field and only commit to URL / localStorage after input settles (few hundred ms). Optionally show a subtle pending/spinner state while debouncing.

Alternative / complementary:

• Do not re-hydrate from localStorage while the operator is actively editing (track focus / dirty flag).
• Flush debounced prefs synchronously before hydration can read stale storage.
• Hydrate only on initial route visit, not on every location.search change when the change originated from the same hook.

Affected

• src/hooks/useChannelListQuery.ts
• src/hooks/useListNameQuery.ts
• src/lib/listPrefs/storage.ts — debouncedMerge*ListPrefs (300 ms)
• src/components/SectionNav/sections/ChannelsListSectionNav.tsx — search TextInput
• Entity list routes / section nav using useListNameQuery (zones, contacts, talk groups, RX group lists)
• src/components/ui/DataTable.tsx — toolbar search prop if wired the same way

Repro (manual)

1. Open Channels (or Zones / Contacts) with a persisted name search from a prior visit (#146).
2. Click the search field and rapidly backspace to clear the filter (or edit several characters quickly).
3. Actual: deleted text snaps back; typing feels "fighting" the field.
4. Expected: field reflects keystrokes until input settles; persisted prefs update after debounce without clobbering active edits.

Repeat on Channels with distance filter / large channel count to reproduce under heavy table updates.

Test plan

• Unit: rapid setNameFilter / clear does not re-hydrate stale localStorage q over the in-progress value.
• Unit or component: debounced commit updates URL + storage after idle period.
• Manual: backspace-to-clear search on zones and channels — text stays cleared.
• Manual: reload without URL params still restores last persisted search when not actively editing.
• Regression: URL params still win on explicit navigation/bookmark (#146 contract).

Related

• Regression from #146 — persist list table sort, columns and filters in localStorage
• Follows #138 — standardised datatables (search in section nav / toolbar)