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/install.rs

@@ -619,7 +619,7 @@ fn build_record(prior: Option<&InstallRecord>, run: &Deployment<'_>) -> InstallR
             files: overlay::file_records(planned),
         }),
         // A `--verify` run installs no sidecar and must not erase the record of one that is
-        // already there; the same reasoning keeps the patch section (Phase 3) and any field a
+        // already there; the same reasoning keeps the patch section and any field a
         // newer installer wrote intact. A record that forgot a running service would make
         // `doctor` and `uninstall` forget it too.
         link: match sidecar {