refactor(log-viewer): tie global listeners to each view's connected life

[lukecotter]

Six views wired global document listeners by hand: added in the constructor,
removed in disconnectedCallback. The constructor runs once and
disconnectedCallback runs on every detach, so a view that came back was deaf.

This was latent, not live: vscode-tabs sets el.hidden rather than detaching,
and LogViewer renders all four panels unconditionally. A conditionally rendered
child gets a brand-new element instead, so its constructor re-runs. It becomes a
real defect the moment anything is wrapped in cache(), rendered lazily, or moved.
Four further sites added a listener and never removed one.

What changed

• core/events/DomListenerController.ts — a ReactiveController taking
  (host, target, handlersMap). It subscribes in hostConnected and unsubscribes
  in hostDisconnected, so a listener lives exactly as long as the host.
• features/find/findEvents.ts — one home for the find event types, replacing the
  copies in flamechart.types.ts and five FindEvt aliases. That also removes a
  SearchOptions that collided by name with a structurally different one.
• Seven views converted. Per-view event subsets are preserved exactly — they are
  behaviour, not sloppiness: the three Database grids skip lv-find-match because
  navigation reaches them through DatabaseView.highlightIndex, and DatabaseView
  skips lv-find-close.
• FindWidget's two leaked listeners are closed.

Handlers are passed as inline arrows, and the controller throws a TypeError
for anything else. useDefineForClassFields is false in both jest.config.js and
log-viewer/tsconfig.json, so field initialisers run in declaration order and a
controller near the top of a class reads undefined for a handler field declared
below it — and addEventListener(name, undefined) is a legal silent no-op.

The defect this makes reachable

CalltreeView destroys its three tables in disconnectedCallback, but the only
build path is gated on the log's first arrival, so a re-attached view came back with
its subscriptions restored and no table. It now rebuilds on connect, for the view
mode on show, under the filters and grouping it was left with. A build overtaken by
a detach no longer wires the table that replaced it, and a visibility wait that
resolved as the view left no longer builds for a detached host.

Not taken here

LogViewer.ts carries the comment "Not really happy this is here, find needs a
refactor" beside a synthetic lv-find dispatched on every tab change. The real fix
is find:* entries in the typed core/events/EventBus.ts, which would delete the
string literals, the casts and that hack. This controller is a stepping stone, not
the destination.

Timeline.ts and ApexLogTimeline still wire by hand — neither is a
ReactiveControllerHost. The Timeline.ts leak is fixed separately.

Testing

New suites for the controller and for CalltreeView's table lifetime, plus
Util.isVisible. Every guard was proven by removing it and watching the matching
test fail. Full suite green.

Checked by hand in the dev host: find in every tab, next/previous, the counter,
Escape, and that switching tabs clears the other tabs' highlights.