fix(input): return a bool|string|string[]|null enum from get_option

`InputInterface::get_option` returned `PhpMixed`, so the negation branch
of `Input::get_option` reproduced PHP's `return !$value;` as
`!value.as_bool().unwrap_or(false)`, which inverts the result for a
string value instead of leaving it `false`. It now returns
`InputOptionValue`, whose `to_bool` is PHP's truthiness cast.

The narrowing also removes the `Vec<PhpMixed>` element handling the
commands carried for array options: `as_array` hands back `&[String]`,
so the `filter_map(|v| v.as_string())` chains at eight call sites
collapse. Its other accessors keep `PhpMixed`'s names and meanings
(`is_null`, `as_bool`, `as_string`, `to_bool`), and
`From<InputOptionValue> for PhpMixed` covers the callers that feed the
value back into an `IndexMap<String, PhpMixed>` or a `PhpMixed`
parameter.

`Input` keeps its parsed options and `InputOption` its defaults as
`PhpMixed`, so `Input::get_option` is where the narrowing happens and
where a value outside the domain panics.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/crates/shirabe/src/command/audit_command.rs b/crates/shirabe/src/command/audit_command.rs
index b6a3a150..d067e074 100644
--- a/crates/shirabe/src/command/audit_command.rs
+++ b/crates/shirabe/src/command/audit_command.rs
@@ -243,12 +243,8 @@ impl Command for AuditCommand {
         let mut ignore_severities: indexmap::IndexMap<String, Option<String>> =
             indexmap::IndexMap::new();
         let cli_severities = input.borrow().get_option("ignore-severity")?;
-        if let Some(list) = cli_severities.as_list() {
-            for sev in list {
-                if let Some(s) = sev.as_string() {
-                    ignore_severities.insert(s.to_string(), None);
-                }
-            }
+        for severity in cli_severities.as_array().unwrap_or_default() {
+            ignore_severities.insert(severity.clone(), None);
         }
         for (k, v) in audit_config.ignore_severity_for_audit.clone() {
             ignore_severities.insert(k, v);