📝 Note two matcher gaps in the backlog

Record the non-exhaustive broad-type hole in the primitive matcher and the
never-typed handler parameters the tagged-union matcher produces when a
property is a union, so both can be picked up as their own work units.

backlog.tasks

@@ -39,6 +39,10 @@ Testing:
     ✔ Run `npm run verify` and check the task off @done
 ☐ Test a literal union widened with `(string & {})` — `"red" | "green" | "yellow" | (string & {})` @medium
     → autocomplete should still offer the literals; arbitrary strings stay assignable and fall through to the fallback
+☐ Type hole when using broad types like string as a universe @high
+    ☐ handlers cannot be exhaustive, yet it is possible to not have a fallback
+    ☐ one test even exploits this, I think for a negative test
+    ☐ does the same type hole exist for tagged-union matchers or primitive matchers only?
 
 Matcher:
 ✔ Clean up: adopt the 3-overload matcher (`src/prototype-ac2.ts`) and delete the prototypes @high @done
@@ -55,6 +59,9 @@ Matcher:
     → `src/primitive.ts` / `src/primitive.test.ts` → `primitive-union.*`
     → `getMatcherW` → `getPrimitiveMatcherW` for symmetry with the tagged-union pair
     → update `src/index.ts`, `development/library.md` and any README references
+☐ when using a union type as a property, the current behavior of tagged union matcher is
+    to pass never to handler parameters
+    → new matcher function needed or can be fixed in tagged union matcher
 
 Bugs:
 ✔ TS 7 LSP server logs `context canceled` on stderr at shutdown @done