feat(kernel): R7b PHP walker — php module, tree-sitter-php 0.24.2 bump, php default-routed (#1380)

Fourth and final R7b batch-2 port, checklist-first recipe
(docs/design/php-kernel-port-checklist.md).

Grammar bump first, validated standalone with the diff ENUMERATED + CLASSIFIED
(unlike rust/ruby the php bump is NOT graph-neutral): tree-sitter-php ^0.22
(tree-sitter-wasms, 2023) → v0.24.2, the full HTML-interleaving `php` variant
(the walker calls LANGUAGE_PHP, never PHP_ONLY) — crate pinned =0.24.2, wasm
built from tag 5b5627f's checked-in php/src/parser.c + scanner.c + shared
common/scanner.h (all sha-matched against the crates.io tarball, ABI 14→15).
Old-vs-new full-init diffs decompose completely into: (1) the anonymous_class
wrapper shape (anon-class nodes/methods re-shape — 2,532 rows), (2) grouped
nested-clause skip (absent in the gate repos, fixture-pinned), (3) 32
formerly-erroring files parsing clean (monolog Level.php, symfony
Request/Response with 8.4 property hooks), (4) a survey-missed category found
at gate time: the 8.4 parenthesis-free `new X()->m()` chaining misparse fix
(86 garbage instantiates refs disappear, precision-positive), plus resolution
RIPPLE proven mechanically (every remaining ref-table flip pairs 1:1 with a
resolved edge on the opposite side; node rows byte-stable outside 1/3/4).

Walker (java.rs chassis + the php specifics) preserves bug-for-bug: the
visitNode hook (const_declaration at ANY scope → bare `constant` nodes, values
never walked; trait-use → implements refs WITH filePath via the ruby port's
REF_FLAG_FILE_PATH wire slot), FIRST-namespace whole-file scoping (braced
namespaces scope nothing; namespaced files DROP top-level const value-ref
targets), the import trio (single/aliased/grouped incl. the nested-clause
skip, include/require static-literal-only, `Foo\Bar::Baz` use refs), the
call-encoding zoo (DOT-joined scoped calls, `this->prop.m` #1251 encoding,
`Cls::factory().m` fluent with inner args dropped, nullsafe `?->` emitting
nothing, unsuppressed literal receivers), interface multi-extends
first-base-only drop, anon-class methods as file-level functions (top) or
vanishing (in-body), property type-hints emitting no field refs, the
final-modifier-as-type signature quirk, HOF-gated string callables
(skipGate) + array callables, and the `name`-node value-ref reader.

Gates: sweeps 0-diff monolog 217/217, laravel-framework 3007/3008, symfony
10726/10737 (13,950 files byte-parity; 12 deferrals = exactly the predicted
genuinely-broken fixtures, ≈0–0.1%); full-init dumps byte-identical ×3
(16.1k/354.2k/702.8k lines); kernel-php-parity suite (torture + drupal
.module + leading-HTML fixtures, CRLF variants, wire-flag pin, defer) + php
grammar-parity row; full suite 2,622 green ×2 under CODEGRAPH_KERNEL_EXPECT=1.
DEFAULT_ROUTED += php (13 languages).

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

scripts/kernel-parity.mjs

@@ -48,7 +48,7 @@ if (paths.length === 0) {
   process.exit(2);
 }
 
-const KERNEL_LANGS = new Set(['typescript', 'tsx', 'javascript', 'jsx', 'java', 'python', 'go', 'c', 'cpp', 'rust', 'csharp', 'ruby']);
+const KERNEL_LANGS = new Set(['typescript', 'tsx', 'javascript', 'jsx', 'java', 'python', 'go', 'c', 'cpp', 'rust', 'csharp', 'ruby', 'php']);
 const EXTS = new Map([
   ['.ts', 'typescript'], ['.mts', 'typescript'], ['.cts', 'typescript'],
   ['.tsx', 'tsx'], ['.js', 'javascript'], ['.mjs', 'javascript'],
@@ -61,6 +61,7 @@ const EXTS = new Map([
   ['.rs', 'rust'], // R7b
   ['.cs', 'csharp'], // R7b
   ['.rb', 'ruby'], ['.rake', 'ruby'], // R7b
+  ['.php', 'php'], ['.module', 'php'], ['.install', 'php'], ['.theme', 'php'], ['.inc', 'php'], // R7b
 ]);
 
 /** Collect candidate files. */