Ignore file was silencing every warning under lib/towerops/**. Root
cause was plt_add_deps: :apps_direct missing Plug/Phoenix/Oban/Decimal
/Redix/ssl/public_key — hundreds of false `unknown_function` warnings
were being papered over.
Expand plt_add_apps to cover the common deps, narrow the ignore file
to real dep-PLT gaps only, and fix two concrete bugs uncovered by the
change:
- ScopedResource.fetch_preload/4: spec was atom() | [atom()] but
callers pass keyword lists (e.g. [rules: :targets]).
- ToweropsNative: tag NIF stubs with @dialyzer :nowarn_function so
dialyzer trusts the @spec instead of the fallback body.
Remaining 328 real warnings surface for follow-up.
