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, 4 insertions, 1 deletions

diff --git a/crates/shirabe/src/command/search_command.rs b/crates/shirabe/src/command/search_command.rs
index 1cd8e59..b9eacf5 100644
--- a/crates/shirabe/src/command/search_command.rs
+++ b/crates/shirabe/src/command/search_command.rs
@@ -199,7 +199,10 @@ impl SearchCommand {
                 }
             }
         } else if format == "json" {
-            // TODO(phase-b): JsonFile::encode takes &PhpMixed; convert Vec<SearchResult> into PhpMixed
+            // TODO(phase-c): faithful JSON output requires SearchResult to retain the raw result
+            // array. PHP's fulltext search passes through arbitrary API fields (downloads, favers,
+            // repository, ...) which the typed SearchResult (name/description/abandoned/url) drops,
+            // so encoding it here would diverge from Composer's output.
             let _ = &results;
             io.write(&JsonFile::encode(&PhpMixed::Null));
         }