ci(lint): forbid empty catch blocks in lib/features without logIgnored #1763

Problem

Nothing stops a new `catch (_) {}` in the UI layer, so the silent failures audited in the sibling issue come back. The repo already has guard tests (for example the shadcn imports ratchet).

Proposal

A guard test (or analyzer rule) over `lib/features` and `lib/shared`: a `catch` block must not be empty; it must call `logIgnored`, the reporting helper, rethrow or handle the error. Start as a ratchet with the current count so existing sites do not block merges, and lower it as the audit proceeds.

Also worth a look in the same pass: the 301 `unawaited(...)` calls; an exception there reaches only `runZonedGuarded` and `debugPrint`.

Part of the error-handling epic.