Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@app/Http/Controllers/System/InstallerController.php`:
- Around line 225-227: The current check if (file_exists(base_path('.env'))) in
InstallerController prevents dbsetup() from running right after envsetup();
remove or replace this gate so dbsetup() is not blocked by the just-created
.env. Specifically, update the InstallerController method that returns
view('system.installer.errors.already-installed') to stop using
file_exists(base_path('.env')) as the sentinel; instead use a separate marker
(e.g., a dedicated installed flag in .env like APP_INSTALLED, a database/lock
file, or a storage/install.lock) and have dbsetup() proceed when only .env
exists but the installed marker is absent. Ensure references to dbsetup() and
envsetup() remain intact and that the new sentinel check prevents real re-entry
after full install without blocking the immediate redirect from envsetup().
- Around line 164-166: The envsetup() method declares a RedirectResponse return
type but returns a View when .env exists (view
'system.installer.errors.already-installed'), causing a type error; fix by
making the method's declared return type compatible with both responses (e.g.,
change signature to return
Illuminate\Http\Response|Illuminate\Http\RedirectResponse or Symfony Response
union) or change the early-exit to return a RedirectResponse instead (redirect
to an appropriate route) so the actual return type matches the method signature;
update the signature for envsetup() and ensure imports for the chosen Response
class are present.