feat(kernel): R7b Ruby walker — ruby module, tree-sitter-ruby 0.23.1 bump, ref-flag wire slot, ruby default-routed (#1379)

Third R7b port, checklist-first recipe (docs/design/ruby-kernel-port-checklist.md).

Grammar bump first, validated standalone (the rust pattern): tree-sitter-ruby
^0.20.1 (tree-sitter-wasms, 2024-02) → v0.23.1 — crate pinned =0.23.1, wasm
built from tag 71bd32f's checked-in parser.c/scanner.c (both sha-matched
against the crates.io tarball; content bump, ABI stays 14). Old-vs-new
full-init dumps: sinatra/jekyll byte-identical; rails = exactly the one
classified hunk (the `recv&.!=` safe-nav operator misparse fix,
`table_name.!` → `table_name.!=`, precision-positive).

Walker (python.rs chassis + the six ruby divergences) preserves bug-for-bug:
the importTypes:['call'] funnel (class-body DSL — attr_accessor, has_many,
define_method incl. its block, sinatra route blocks — emits NOTHING at
non-body scope), hook-handled module multiply-capture (nested modules re-scan
their subtree per level after popping — `this.hooked` fn-refs from class AND
module AND file), the sibling-scan visibility trio (bare `private` invisible;
`private :sym`/`private def` poison all later defs; the inner def stays
public), bare-call statements (do…end body_statement emits, brace-block
block_body doesn't), `.new` instantiates with last-`::`-segment names,
constant-receiver references refs, require/require_relative path refs
(posix-normalized, `.rb`-suffixed, `Kernel.require` and interpolated-path
quirks included), `=begin` docstring marker survival, and the reverse-order
value-ref DFS.

Wire v2: the hook's mixin `implements` refs carry `filePath: ctx.filePath` —
the ONE extraction-ref denormalized field (php's trait-use refs share the
shape). RefRow's first pad byte becomes a flags slot (REF_FLAG_FILE_PATH);
decode re-attaches its own filePath parameter; KERNEL_ABI_VERSION 1→2 on both
sides (mismatched dist/.node pairs degrade to wasm, as designed).

Gates: sweeps 0-diff sinatra 147/147, jekyll 164/164, rails 3452/3452 (3,763
files, 0 deferrals — ruby error incidence 0.00%, any deferral = walker bug);
full-init dumps byte-identical ×3 (7.2k/9.4k/375.6k lines); kernel-ruby-parity
suite (torture + CRLF + wire-flag pin + defer) + ruby grammar-parity row;
full suite 2,613 green ×2 under CODEGRAPH_KERNEL_EXPECT=1 (one unrelated
mcp-initialize timing flake under parallel load, passes solo 3/3 ×3).
DEFAULT_ROUTED += ruby (12 langs).

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

codegraph-kernel/Cargo.lock

@@ -59,6 +59,7 @@ dependencies = [
  "tree-sitter-java",
  "tree-sitter-javascript",
  "tree-sitter-python",
+ "tree-sitter-ruby",
  "tree-sitter-rust",
  "tree-sitter-typescript",
 ]
@@ -562,6 +563,16 @@ dependencies = [
  "tree-sitter-language",
 ]
 
+[[package]]
+name = "tree-sitter-ruby"
+version = "0.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be0484ea4ef6bb9c575b4fdabde7e31340a8d2dbc7d52b321ac83da703249f95"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "tree-sitter-rust"
 version = "0.24.2"