PHP `use` imports stored as raw statement text; importers_of and impact-radius return 0 for PHP classes

[stefanws0]

code-review-graph version

2.3.6 (run as the MCP server). Also reproduced on the 2.3.2 CLI; the root cause
is present in both.

Operating system

macOS 15 (Darwin 24.5.0), Apple Silicon.

Python version

Python 3.14.4

AI platform

Claude Code (MCP server over stdio).

Output of code-review-graph status

From the minimal reproducer below:

Nodes: 6
Edges: 5
Files: 3
Languages: php

Steps to reproduce

1. Create a minimal PSR-4 PHP project and build the graph:

mkdir -p repro/src/App/Domain/Entity repro/src/App/Service repro/src/App/Api
cd repro && git init -q
printf '<?php\nnamespace App\\Domain\\Entity;\nclass Job {}\n'                                   > src/App/Domain/Entity/Job.php
printf '<?php\nnamespace App\\Service;\nuse App\\Domain\\Entity\\Job;\nclass MatchService {}\n'  > src/App/Service/MatchService.php
printf '<?php\nnamespace App\\Api;\nuse App\\Domain\\Entity\\Job;\nclass JobController {}\n'      > src/App/Api/JobController.php
git add -A
code-review-graph build

2. Ask for the importers of the Job class (via the MCP query_graph tool, or
   the package API):

from code_review_graph.tools.query import query_graph
query_graph("importers_of", "<abs>/src/App/Domain/Entity/Job.php", repo_root="<abs>")

Expected vs actual behavior

Expected: importers_of(Job.php) returns the two files that
use App\Domain\Entity\Job; (MatchService.php and JobController.php).
Equivalently, the IMPORTS_FROM edges should target the resolved path of
Job.php.

Actual: importers_of returns 0 results. Inspecting the graph shows the
IMPORTS_FROM edge targets are the raw use statement text instead of a
resolved file path or FQN:

src/App/Api/JobController.php      ->  use App\Domain\Entity\Job;
src/App/Service/MatchService.php   ->  use App\Domain\Entity\Job;

importers_of(Job.php)  ->  Found 0 result(s)

The same defect makes tests_for and inheritors_of return nothing for PHP
classes, hides PHP importers from the upstream side of get_impact_radius, and
(because resolve_bare_call_targets uses IMPORTS_FROM targets to disambiguate
cross-file CALLS) degrades PHP call resolution too. On a real Symfony/PHP
codebase this meant a core entity imported by 452 files showed 0 importers.

Additional context

Root cause: _extract_import in parser.py has a per-language branch for
Python, JS/TS, Go, Rust, Java, C#, Scala, Dart, Julia and others, but none for
PHP, so PHP use statements fall through to the raw-text fallback
(imports.append(text)) and store the entire statement as the edge target.
There is also no PHP case in _do_resolve_module (Java resolves import a.b.C;
to the class file; PHP needs the analogous mapping).

A fix is proposed in #573: a PHP branch in _extract_import (recording the FQN,
handling as aliases, grouped use A\{B, C}, and use function / use const)
plus a PHP branch in _do_resolve_module that resolves the FQN to an absolute
.php path by walking up from the importing file, mirroring the Java resolver.