Align metadata/viewport build messages with overlay wording
- Rename disallowedDynamicMetadataMessage -> createDynamicOrRuntimeMetadataError
and disallowedDynamicViewportMessage -> createDynamicOrRuntimeViewportError
to match createDynamicOrRuntimeBodyError naming from #92638
- Return Error instead of string, add JSDoc comments matching body error
- Use "in" instead of "inside" across all build messages to match overlay
- Update disallowed* headlines to "Next.js encountered..." pattern
Made-with: Cursor
