fix(apply): reject reserved module names in validate_bundle (parity)

The interactive create path rejects a module whose name shadows a built-in
SDK namespace (`kv`, `secrets`, …) so `import "kv"` can't resolve to a user
module, but `pic apply`'s `validate_bundle` skipped the check — a parity gap
that let a manifest create what the dashboard forbids. Gate it on
`ScriptKind::Module` and share the same `RESERVED_MODULE_NAMES` const (now
`pub(crate)`); endpoints remain unrestricted.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/manager-core/src/apply_service.rs

@@ -886,6 +886,15 @@ impl ApplyService {
                 )));
             }
             let res = if s.kind == ScriptKind::Module {
+                // Parity with the interactive create path (`api.rs`): a module
+                // may not shadow a built-in SDK namespace, or `import "kv"`
+                // could resolve to a user module instead of the real bridge.
+                if crate::api::RESERVED_MODULE_NAMES.contains(&s.name.as_str()) {
+                    return Err(ApplyError::Invalid(format!(
+                        "script `{}`: reserved module name (shadows a built-in SDK namespace)",
+                        s.name
+                    )));
+                }
                 self.validator.validate_module(&s.source)
             } else {
                 self.validator.validate(&s.source)