OAK-12239: Remove FT_PREFETCH_OAK-9780 and remove 'no prefetch' code path

[reschke]

No description provided.

[rishabhdaim]

After dropping sys-prop setup, consider adding a test that calls DocumentNodeStore.prefetch() (not CacheWarming directly) with default builder setup and asserts cache warming — that would lock in the always-on store path this PR introduces.

[reschke]

I don't quite understand; is this about adding a test that we should have had before?

[rishabhdaim]

see #2934 (comment)

[rishabhdaim]

1. oak-store-document/AGENTS.md still lists FT_PREFETCH_OAK-9780 and setPrefetchFeature() — both removed here.
2. Store-level prefetch is always on when prefetch() is called; PrefetchDispatcher is unrelated and still gated by prefetchExternalChanges.
3. Please update the Prefetch section and drop that row from the toggles table.

[reschke]

@rishabhdaim - thx for the review, and please see my questions (PR minimally updated).

(this shows that even removing a toggle is not totally trivial)

[rishabhdaim]

Outside this diff — CacheWarmingTest.prefetch() (lines ~138–169):

prefetch() still exercises CacheWarming directly, so it won't catch a regression in DocumentNodeStore.prefetch() now that prefetch is always-on at the store layer. Call the store API instead (same assertions):

-        CacheWarming cw = new CacheWarming(ds);
         DocumentNodeStore store = builderProvider.newBuilder().setAsyncDelay(0)
                 .setDocumentStore(ds).getNodeStore();
         ...
-        cw.prefetch(children, store.getRoot());
+        store.prefetch(children, store.getRoot());
         ...
-        cw.prefetch(paths, store.getRoot());
+        store.prefetch(paths, store.getRoot());

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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[github-actions]

Commit-Check ✔️

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud