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/tests/configuration.py

@@ -159,11 +159,28 @@ try:
     send({'jsonrpc': '2.0', 'method': 'textDocument/didOpen', 'params': {'textDocument': {'uri': file.as_uri(), 'languageId': 'java', 'version': 1, 'text': source}}})
     request('java/buildWorkspace', True)
     assert 'openidea.java.configuration' in init['capabilities']['executeCommandProvider']['commands'], init
+    def warmup(action='start'):
+        return request('workspace/executeCommand', {'command': 'openidea.java.configuration.warmup', 'arguments': [action, [(project / 'application.yml').as_uri()]]})
+    # Queuing is cheap and idempotent; the index is built by a background job.
+    queued_at = time.perf_counter()
+    queued = warmup()
+    assert queued['scheduled'] and queued['pending'] > 0 and not queued['completed'], queued
+    assert warmup()['pending'] == queued['pending'], 'a repeated start queued the project twice'
+    deadline = time.monotonic() + 90
+    while time.monotonic() < deadline:
+        warmed = warmup('status')
+        if not warmed['scheduled']: break
+        time.sleep(.1)
+    assert not warmed['scheduled'] and warmed['completed'], warmed
+    assert warmup()['pending'] == 0, 'a repeated start queued a warmed project again'
+    prewarm_seconds = time.perf_counter() - queued_at
     results = {}
     for key in ['app', 'vendor', 'app.time-out', 'app.enabled', 'app.nested.url', 'app.clients[0].url', 'app.routes.east.url', 'app.tags[0]', 'app.labels.region', 'app.labels[region.name]', 'constructor.remote-name', 'record.name', 'bean.url', 'app.backup', 'app.required', 'vendor.port', 'extra.url']:
         start = time.perf_counter()
         result = query(key)
         results[key] = {'seconds': time.perf_counter() - start, 'response': result}
+        if key == 'app':
+            assert result['generation'] in warmed['completed'].values(), ('the first lookup rebuilt the warmed index', result, warmed)
         assert result['locations'], (key, result)
     attached = request('java/classFileContents', {'uri': results['vendor.port']['response']['locations'][0]['uri']})
     assert attached and 'LibrarySettings' in attached and 'port' in attached, attached
@@ -238,7 +255,9 @@ try:
     send({'jsonrpc': '2.0', 'method': 'textDocument/didClose', 'params': {'textDocument': {'uri': file.as_uri()}}})
     restored = query('app.nested.url')
     assert restored['locations'], restored
-    evidence = {'stress': os.environ.get('OPENIDEA_CONFIGURATION_STRESS') == '1', 'editRebuildMs': edit_ms, 'cases': results, 'warmMedianMs': sorted(warm)[len(warm)//2] * 1000, 'warmMaxMs': max(warm) * 1000, 'generations': [generation, after_save, after_close]}
+    cancelled = warmup('cancel')
+    assert not cancelled['scheduled'] and cancelled['pending'] == 0, cancelled
+    evidence = {'stress': os.environ.get('OPENIDEA_CONFIGURATION_STRESS') == '1', 'prewarmSeconds': prewarm_seconds, 'editRebuildMs': edit_ms, 'cases': results, 'warmMedianMs': sorted(warm)[len(warm)//2] * 1000, 'warmMaxMs': max(warm) * 1000, 'generations': [generation, after_save, after_close]}
     (work / 'evidence.json').write_text(json.dumps(evidence, indent=2))
     print(json.dumps(evidence, indent=2))
 finally: