feat(phase-c): resolve PhpMixed-conversion phase-b TODOs

Implement the foundational PhpMixed conversion infrastructure
(From<bool|i64|f64|String>, order-sensitive PartialEq matching PHP ===)
and resolve the category-G phase-b TODOs that depend on it:

- Fix VCS driver cache paths that discarded parsed JSON or diverged on
  null caches (svn/forgejo/gitlab/git-bitbucket/github).
- Wire up real conversions previously stubbed or dropped: suggests
  platform config, audit ignore-severities, composer_repository search
  and ProviderInfo, class_loader prefix/classmap merges, locker lock
  diff comparison, advisory JSON serialization, SPDX license fields.
- Make GenericRule take a typed ReasonData; populate RULE_ROOT_REQUIRE
  with the constraint and convert PhpMixed at the call sites.

1 files changed, 1 insertions, 2 deletions

diff --git a/crates/shirabe/src/json/json_file.rs b/crates/shirabe/src/json/json_file.rs
index b8372b9..a185084 100644
--- a/crates/shirabe/src/json/json_file.rs
+++ b/crates/shirabe/src/json/json_file.rs
@@ -349,7 +349,7 @@ impl JsonFile {
         }
 
         // PHP: $schemaData = (object) ['$ref' => $schemaFile, '$schema' => "https://json-schema.org/draft-04/schema#"];
-        // TODO(phase-b): represent (object) cast as PhpMixed::Array or a dedicated stdClass shim
+        // A string-keyed `PhpMixed::Array` serializes as a JSON object, matching the (object) cast.
         let mut schema_data: PhpMixed = {
             let mut m = indexmap::IndexMap::new();
             m.insert(
@@ -367,7 +367,6 @@ impl JsonFile {
 
         if schema == Self::STRICT_SCHEMA && is_composer_schema_file {
             schema_data = json_decode(&file_get_contents(&schema_file).unwrap_or_default(), false)?;
-            // TODO(phase-b): mutate object properties; using PhpMixed::Array we set keys
             if let PhpMixed::Array(map) = &mut schema_data {
                 map.insert(
                     "additionalProperties".to_string(),