feat(kernel): R4 — Java port with Lombok synthesis, gate passed, default-on

Java joins the native kernel (codegraph-kernel/src/java.rs), mirroring
the wasm extractor's Java paths bug-for-bug: package namespaces,
imports, javadoc, annotations→decorates, type_list inheritance,
static-final constants, enum constants, anonymous classes (including
the TS side's 0-based-line quirk on the extends ref), method_invocation
calls with the this.field unwrap and the Foo.getInstance().bar() chain
encoding (#645/#608), static-member value reads, method-reference
fn-refs (#756), value-reference edges, and the full Lombok member
synthesizer (#912: Getter/Setter/Data/Value/Builder/ToString/
EqualsAndHashCode/Slf4j-family with taken-member dedup). The shared
docstring/textutil modules moved to crate level. Grammar:
tree-sitter-java 0.23.5, with the wasm grammar vendored from the same
tag (parser.c sha-matched) replacing tree-sitter-wasms' 2023-era build.

Gate (plan §4c): extraction sweeps 100% — gson 262/262, retrofit
341/341, dubbo 4,048/4,048 — plus a Java torture fixture in npm test;
full-init dump-diffs byte-identical on gson (49,766 rows), retrofit
(62,735), and dubbo (441,266 rows); all R2/R3 repos re-verified; Linux
container runs all 23 kernel tests green under CODEGRAPH_KERNEL_EXPECT=1.

The gate caught a real cross-language bug: fn-ref dedupe and value-ref
self-target checks must compare node ID STRINGS, not node-table rows —
ids collide for same-(kind, name, line) nodes, which minified one-line
bundles hit routinely (retrofit's website JS exposed it; latent in the
TS/JS walker since R2, never released). Fixed in both walkers.

Benchmark honesty: dubbo fresh-init on an 11-core Mac is ~flat
(parse-loop wall 5,020→4,394ms; total ~11.3s both arms) because that
wall is main-thread-bound (reads + store), not worker-CPU-bound — the
§6 expectation assumed otherwise. Where worker CPU binds the kernel
delivers: dubbo on a 2-CPU/6GB container drops 27.8-28.6s → 22.3-22.8s
(~1.25×). The identified lever for the many-core headline is decoding
kernel buffers directly into store rows (skipping per-node JS object
materialization); the buffer contract already carries everything.

DEFAULT_ROUTED now includes java. Full suite: 2,467 tests pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/extraction/grammars.ts

@@ -279,15 +279,17 @@ export async function initGrammars(): Promise<void> {
  * parse identically and per-language routing stays graph-neutral:
  *   - tree-sitter/tree-sitter-typescript v0.23.2 (f975a62) → typescript + tsx
  *   - tree-sitter/tree-sitter-javascript v0.25.0 (44c892e) → javascript + jsx
+ *   - tree-sitter/tree-sitter-java v0.23.5 (94703d5) → java
  * Built from each repo's CHECKED-IN parser.c (no `generate`) with
- * tree-sitter-cli 0.25.10 `build --wasm` — the same tables crates.io compiles.
+ * tree-sitter-cli 0.25.10 `build --wasm` — the same tables crates.io compiles
+ * (parser.c sha-matched against the crates.io tarball).
  * The kernel-grammar-parity test asserts this alignment; bump the crate and
  * the vendored wasm together.
  */
 const VENDORED_WASM_LANGS: ReadonlySet<GrammarLanguage> = new Set([
   'pascal', 'scala', 'lua', 'luau', 'csharp', 'r', 'cfml', 'cfscript', 'cfquery',
   'cobol', 'vbnet', 'erlang', 'terraform', 'arkts', 'nix',
-  'typescript', 'tsx', 'javascript', 'jsx',
+  'typescript', 'tsx', 'javascript', 'jsx', 'java',
 ]);
 
 /** Absolute path of a language's grammar WASM (vendored or tree-sitter-wasms). */

src/extraction/kernel/index.ts

@@ -33,6 +33,7 @@ const DEFAULT_ROUTED: ReadonlySet<Language> = new Set<Language>([
   'tsx',
   'javascript',
   'jsx',
+  'java',
 ]);
 
 /**