refactor(install): Slice A — align install.rs with Composer's InstallCommand pipeline

- Match Composer's deprecation wording for --dev and --no-suggest (A1)
- Add missing URL to lock-fallback warning (A2)
- Reorder arg validation to match InstallCommand::execute order (A3)
- Rename collect_install_* helpers to verify_lock_* and consolidate
  into a single verify_lock() entry point (A4)
- Couple classmap_authoritative=true → optimize_autoloader=true,
  mirroring Composer's setter side-effects (Installer.php 1263-1272) (A5)
- Centralise is_platform_package in mozart_core::platform, removing
  divergent local copies from install.rs and update.rs (A6)
- Move compute_operations, topological_sort, alias helpers, and
  locked_to_installed_entry into mozart-registry::installer_executor::
  transaction, re-exported from the parent module (A8)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/crates/mozart-registry/src/installer_executor/mod.rs b/crates/mozart-registry/src/installer_executor/mod.rs
index c29e32c..4ddad66 100644
--- a/crates/mozart-registry/src/installer_executor/mod.rs
+++ b/crates/mozart-registry/src/installer_executor/mod.rs
@@ -20,9 +20,14 @@ use crate::lockfile::{LockAlias, LockedPackage};
 
 pub mod filesystem;
 pub mod trace_recorder;
+pub mod transaction;
 
 pub use filesystem::FilesystemExecutor;
 pub use trace_recorder::TraceRecorderExecutor;
+pub use transaction::{
+    Action, StaleInstalledAlias, compute_operations, compute_stale_installed_aliases,
+    locked_to_installed_entry, previously_installed_alias_versions,
+};
 
 /// One install or update operation handed to [`InstallerExecutor::install_package`].
 #[derive(Debug, Clone, Copy)]