Perf: Simplify static metadata handling (#92630)
### What?
Avoid running the generic `fillMetadataSegment(..., true)` path for
static metadata routes.
This PR adds a dedicated static metadata URL resolver, uses it from the
existing TypeScript static call sites, and precomputes static metadata
URLs in Turbopack loader tree codegen instead of waiting on
`props.params` at runtime.
### Why?
Static metadata files like `favicon.ico`, `icon.png`, and other static
metadata images do not need request-time dynamic path interpolation.
The old path reused logic that was designed to also support dynamic
metadata routes, which meant extra route-regex work even when the final
URL was already statically known apart from the existing `-` placeholder
and route-group / parallel-route suffix semantics.
### How?
- Added a static-only metadata URL helper in `get-metadata-route.ts`
that:
- normalizes app path segments,
- replaces dynamic and catch-all segments with `-`,
- preserves the existing metadata filename suffix logic for route groups
and parallel routes.
- Kept `fillMetadataSegment()` for dynamic metadata routes, but
short-circuited the `isStatic` path to the new helper.
- Switched TypeScript static metadata call sites to use the static
helper directly:
- build tree display path generation,
- dev bundler static metadata mapping,
- webpack static metadata image loader output.
- Updated Turbopack static metadata codegen to emit the final static URL
string instead of calling `fillMetadataSegment(..., true)` with `await
props.params`.
- Added focused coverage for:
- root favicon,
- static metadata under dynamic parents,
- route-group / parallel-route suffix behavior,
- unchanged dynamic metadata interpolation.
Closes NEXT-
Fixes #
<!-- NEXT_JS_LLM_PR -->
