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, 2 insertions, 1 deletions

diff --git a/crates/shirabe/src/advisory/any_security_advisory.rs b/crates/shirabe/src/advisory/any_security_advisory.rs
index c48df33..b6df764 100644
--- a/crates/shirabe/src/advisory/any_security_advisory.rs
+++ b/crates/shirabe/src/advisory/any_security_advisory.rs
@@ -3,7 +3,8 @@ use crate::advisory::PartialSecurityAdvisory;
 use crate::advisory::SecurityAdvisory;
 use shirabe_semver::constraint::AnyConstraint;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, serde::Serialize)]
+#[serde(untagged)]
 pub enum AnySecurityAdvisory {
     Partial(PartialSecurityAdvisory),
     Full(SecurityAdvisory),