docs(installer): drop phase references that are now this build's behaviour

Five comments described the patch tier as work a later phase would do. It is
this phase, so they read as stale the moment the code landed.

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

src/paths.rs

@@ -145,7 +145,8 @@ mod tests {
     #[test]
     fn the_installers_own_files_sit_in_the_state_dir() {
         // Everything the installer owns lives together, so `uninstall` (Phase 4) has one place to
-        // clean and `doctor` has one place to read. The cached patch set joins them in Phase 3.
+        // clean and `doctor` has one place to read. The cached patch set and the pre-image
+        // copies of every patched file live there too.
         let l = platform_layout();
         assert_eq!(l.install_record().parent(), Some(l.state_dir.as_path()));
         assert_eq!(l.sidecar_config().parent(), Some(l.state_dir.as_path()));