perf(java): prewarm configuration navigation and share results between hover and click (#947)

Configuration navigation from YAML/properties still waited for a cold index the first
time and repeated the lookup between the ⌘-hover probe and the click.

- Trusted projects with a Maven/Gradle/Eclipse build file start Java shortly after
  opening. Once JDT reports ServiceReady, the app calls the new
  openidea.java.configuration.warmup command: a low-priority background job builds
  the configuration index one project at a time (open YAML/properties modules first),
  waits for workspace builds, has a 30 s budget per project, and only fills free cache
  room.
- Index builds take a cancellable per-project lock instead of one global lock, so a
  background build never delays another project, and a warmed snapshot is dropped
  if the Java model changed meanwhile.
- In YAML/properties the editor underlines the whole key (hyphens and dots
  included), hover and Go to Definition share one bounded request per key, and the
  declaration chooser names the whole key.

Bundle java-usages 1.6.0 is rebuilt reproducibly with build.py against JDT LS
1.63.0-202610191322 (SHA-256 33cfa1bb…). The real-JDT harness checks that the first
lookup reuses the warmed index.

Co-authored-by: qjlqyf <109515705+qjlqyf@users.noreply.github.com>

java/java-usages/README.md

@@ -57,7 +57,7 @@ is not a claim of full IntelliJ feature parity.
 ## Rebuild and delivery
 
 The checked-in jar is embedded by ide-sdk `include_bytes!`, installed as
-`java-usages-1.5.0.jar`, and added alongside existing initialization bundles.
+`java-usages-1.6.0.jar`, and added alongside existing initialization bundles.
 Users need no compiler, Maven or Python. Manifest/install version must change
 when replacing the bundle because OSGi caches bundles.
 
@@ -83,6 +83,10 @@ Version 1.5.0 answers `{locations, complete}`: `complete` when the type is decla
 dependencies' implementations after the first ones. The search also covers the project's Kotlin
 classes attached by the Kotlin bridge; its reproducible SHA-256 is
 `7588748c2797f9da2beb209714a75c29b4e31b155f095329bfb7e399d807c20a`.
+Version 1.6.0 adds `openidea.java.configuration.warmup`, which builds configuration indexes in a
+low-priority background job after import, and builds them under cancellable per-project locks
+instead of one global lock; its reproducible SHA-256 is
+`33cfa1bb8489247ffeb6fc8249966c8a2955b7b2858c8169a70486eb70ade696`.
 
 ```sh
 export PATH=/path/to/jdk25/bin:$PATH