feat(kernel): R7b Rust walker — rustlang module, tree-sitter-rust 0.24.2 bump, rust default-routed (#1371)

First R7b language port. Grammar: tree-sitter-rust pinned =0.24.2 + wasm
vendored from tag 77a3747 (parser.c/scanner.c sha-matched against the
crates.io tarball), replacing the 2023 ABI-14 tree-sitter-wasms build —
the bump alone is precision-positive on the wasm path (receiver-qualified
instance-method resolutions replace ambiguous bare-name matches; node
sections byte-identical on ripgrep/tokio).

Walker mirrors the TS reference bug-for-bug per
docs/design/rust-lang-kernel-port-checklist.md (survey artifact): dead-code
isAsync, impl-pushes-no-scope, the impl-Trait-for-Generic<T> trait-receiver
quirk, phantom const identifiers, use-binding triple emission,
wildcard-use-emits-nothing, scoped-supertrait drop, chained-call re-encode
gated on scoped_identifier, Rocket route macros body-only.

Gates: parity sweeps 0 diffs — ripgrep 101/101, tokio 790/790,
rust-analyzer 1217/1488 (271 deferrals are token-macro-table sources that
error on BOTH arms — grammar-inherent); full-init dump-diffs byte-identical
on all three (3,857 / 13,440 / 39,030 nodes); kernel-rustlang-parity suite
(torture + CRLF + defer) in npm test; full suite green x2 with
CODEGRAPH_KERNEL_EXPECT=1.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -11,7 +11,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### New Features
 
-- Indexing TypeScript, TSX, JavaScript, JSX, Java, Python, Go, C, and C++ projects is faster: parsing and symbol extraction now run in a native engine when a prebuilt binary is available for your platform (release bundles include one), producing exactly the same graph — verified byte-for-byte against the previous engine on real repositories, from small libraries up to vscode-, dubbo-, django-, git-, and protobuf-scale codebases (Lombok-generated members, C function-pointer tables, and Unreal-Engine-style macro-heavy headers included; CUDA and Metal sources ride the C++ path). The speedup is largest on resource-constrained machines like CI runners. No setup needed: platforms without the native binary, and individual files with syntax errors, automatically use the previous engine, and `CODEGRAPH_KERNEL=0` turns the native path off entirely.
+- Indexing TypeScript, TSX, JavaScript, JSX, Java, Python, Go, C, C++, and Rust projects is faster: parsing and symbol extraction now run in a native engine when a prebuilt binary is available for your platform (release bundles include one), producing exactly the same graph — verified byte-for-byte against the previous engine on real repositories, from small libraries up to vscode-, dubbo-, django-, git-, protobuf-, tokio-, and rust-analyzer-scale codebases (Lombok-generated members, C function-pointer tables, and Unreal-Engine-style macro-heavy headers included; CUDA and Metal sources ride the C++ path). The speedup is largest on resource-constrained machines like CI runners. No setup needed: platforms without the native binary, and individual files with syntax errors, automatically use the previous engine, and `CODEGRAPH_KERNEL=0` turns the native path off entirely.
 - Reference resolution now runs in parallel on large projects. When a project has enough pending references to make it worthwhile (roughly 150k+, typical for big Java/Kotlin/Spring codebases), resolution fans out across worker threads while results are applied in the exact order the single-threaded path would have used — the graph comes out byte-for-byte identical, about twice as fast end-to-end on a 4,000-file Java project in our testing. Small projects keep the single-threaded path automatically (the fan-out costs more than it saves there). Set `CODEGRAPH_NO_PARALLEL_RESOLVE=1` to disable, or `CODEGRAPH_PARALLEL_RESOLVE_MIN=<count>` to tune when it engages.
 - Indexing large projects got another sizeable speedup — about a quarter less wall-clock on the same 4,000-file Java project, with the graph still byte-for-byte identical. Two changes: the database no longer interleaves expensive checkpoint housekeeping into the middle of resolution on a fresh index (it's folded once at the end instead), and while one batch's results are being written out, the worker threads are already resolving the next batch instead of sitting idle.
 - The dynamic-dispatch analysis that runs at the end of indexing (callback, event, and framework wiring) now runs its passes in parallel on large projects, cutting that stage roughly in half there — and a pass that crashes now retries safely instead of failing the whole index, which also makes very large codebases that previously died in this stage more likely to index to completion. Graphs remain byte-for-byte identical.
@@ -28,6 +28,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### Fixes
 
 - TypeScript, TSX, and JavaScript files now parse with up-to-date grammars — modern syntax such as `using` declarations and import attributes no longer trips parse errors that could drop surrounding symbols. (The previously bundled grammars dated from 2023.)
+- Rust files also parse with an up-to-date grammar now (the previously bundled build dated from 2023), which additionally sharpens method-call attribution: calls through struct fields resolve with receiver context instead of falling back to ambiguous bare-name matching, removing a class of wrong call edges on common names like `len` and `start`.
 - Searching or exploring by field names now finds the code that defines them. A query made of object keys or API field names (`profileInfo isTrialEligible quotaInfo billingMethod`) used to return unrelated results while the defining files never appeared, because three retrieval steps each dropped multi-word camelCase terms: an internal case-comparison bug, a match step that only considered classes (never functions or methods), and exploration seeding that required exact symbol-name matches. All three are fixed — `codegraph_explore` with a bag of field names now surfaces the controllers and services that assemble those fields. (#1196)
 - `codegraph.json`'s `includeIgnored` works again for the "folder of repos" layout: when one `.gitignore` rule covers a parent directory (`/repos/`) holding several embedded git repositories, opting in the individual repos (`"includeIgnored": ["repos/a/"]` — the exact spelling `codegraph init`'s own hint suggests) previously matched nothing and indexed zero files, looping the same suggestion back at you. Both spellings now work — name the parent directory to opt in everything under it, or name individual repos to opt in just those — and the hint no longer re-suggests repos that are already configured. (#1295)
 - Method calls on literals (`", ".join(...)` in Python, `"x".split(...)` in JavaScript, and the like) no longer produce call edges to unrelated project functions that happen to share the builtin's name — a codebase with a function called `join`, `get`, or `update` could show phantom callers from every string-builtin use. Additionally, a function nested inside another function is now only matched as a call target from inside its container, since it isn't reachable from anywhere else. Blast-radius and affected-test results get cleaner on Python and JavaScript codebases especially. (#1230)