* refactor(linters): add prefer-coerce-array rule
Refs #45217
`x ?? []` and `coerceArray(x)` say the same thing, but only the second
one is searchable and consistent. The rule flags a `??` whose default is
a bare `[]` literal; a non-empty default or an asserted `([] as Foo[])`
still passes.
Applying it across `lib/` surfaced three spots the helper cannot cover,
which keep `?? []` with a disable comment or a narrower fix:
- `package-files.ts` destructures a tuple, which `coerceArray()` widens
- `generate.spec.ts` defaults `matchAll()`, an iterator rather than an array
- `mise/upgradeable-tooling.ts` declares a `Record` return, so its
`?? []` fallback was wrong to begin with and becomes `coerceObject()`
* refactor(platform/github): hoist the GHE version header lookup
`Object.entries(...).find()` returns a tuple, and defaulting it with
`?? []` only to destructure the second element reads as an array
default when it is not one. Name the found entry instead, which drops
the `?? []` rather than routing a tuple through `coerceArray()`.
Sebastian Poxhofer