fix(java): resolve lockfile URLs from metadata - #9719

Greptile Summary

This PR updates core:java lockfile generation to resolve download URLs and checksums directly from the mise Java metadata API, making the process platform-aware so mise lock --platform can record assets for non-host platforms (e.g., Windows ZIPs from a Linux host). It also preserves release_type in locked options and adds an e2e test.

• Adds fetch_java_metadata_for_target with an in-memory tokio::sync::Mutex-backed cache keyed by (release_type, platform_key), reusing the existing CacheManager-backed host cache when the target matches the host platform.
• Refactors download_java_metadata, java_os, java_arch, and the file-type filter to be Platform-aware instead of relying on compile-time or host-only globals, and extracts to_version_string(&Platform) from Display for clean cross-platform key generation.
• Implements resolve_lock_info and resolve_lockfile_options on the Backend trait for JavaPlugin, covering mise install --locked --dry-run from a fresh lockfile without requiring a prior install.

Confidence Score: 5/5

Safe to merge — changes are well-scoped to Java metadata fetching and lockfile generation with no impact on the install or version-listing hot paths for users who don't use mise lock.

The core refactoring (platform-aware metadata fetch, to_version_string, file-type filter) correctly handles all platform branches including musl, FreeBSD host, Windows cross-lock, and the host-cache reuse shortcut. The tokio::sync::Mutex in-memory cache prevents redundant HTTP round-trips within a single invocation. The e2e test exercises both the host and cross-platform (Windows) lock paths plus the --locked --dry-run flow.

No files require special attention.

Important Files Changed

_{Reviews (4): Last reviewed commit: "test(java): handle musl in lockfile e2e" | Re-trigger Greptile}

@roele Sorry for pinging. Are there any reasons the mise lock was not supported for Java?
I think I still need to fix this PR, but I would like to know if I'm not missing something important here.

@risu729 Not that i am aware of. Even though Java might be a bit less prone to incompatibilities between minor or even major versions, pinning still might be helpful.

I see, thanks! I just hit this while using mise lock and mise install --locked, but it's not a standard workflow.