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, 0 insertions, 2 deletions

diff --git a/crates/shirabe/src/installer/library_installer.rs b/crates/shirabe/src/installer/library_installer.rs
index daf5e33..decc1c2 100644
--- a/crates/shirabe/src/installer/library_installer.rs
+++ b/crates/shirabe/src/installer/library_installer.rs
@@ -55,7 +55,6 @@ impl LibraryInstaller {
         let filesystem = filesystem
             .unwrap_or_else(|| std::rc::Rc::new(std::cell::RefCell::new(Filesystem::new(None))));
         let vendor_dir = rtrim(
-            // TODO(phase-b): Config::get returns PhpMixed; coerce to String via get_str.
             &composer_ref
                 .get_config()
                 .borrow_mut()
@@ -74,7 +73,6 @@ impl LibraryInstaller {
                         .unwrap_or_default(),
                     Some("/"),
                 ),
-                // TODO(phase-b): Config::get returns PhpMixed; coerce to String via get_str.
                 composer_ref
                     .get_config()
                     .borrow_mut()