[#3094] Derived the previous install state at run time instead of storing '.vortex-manifest.json' in the project.

.vortex/docs/content/updating-vortex.mdx

@@ -65,6 +65,8 @@ Specifically check if any environment variables were added or changed.
    It may be a good idea to commit changes in smaller chunks to make it easier
    to review and revert if necessary.
 
+   Where the update replaced a file your project had changed, `.logs/vortex-update.md` records the replaced change alongside the change the new version brings. Work through it to re-apply your changes, then delete the entries you have resolved. The file is not tracked in Git.
+
    Your `composer.json` has most likely deviated from the **Vortex** version,
    so review the package version changes carefully. We recommend temporarily
    reverting the changes to `composer.json` and `composer.lock` to preserve

.vortex/installer/src/Command/InstallCommand.php

@@ -224,7 +224,13 @@ protected function execute(InputInterface $input, OutputInterface $output): int
           $version = $this->getRepositoryDownloader()->download($this->artifact, $this->config->get(Config::TMP), $release_prefix);
           $this->config->set(Config::VERSION, $version);
           $this->fileManager->snapshotTemplate();
-          $this->fileManager->snapshotPreviousTemplate($this->getRepositoryDownloader(), $this->artifact);
+          $this->fileManager->snapshotPreviousTemplate(
+            $this->getRepositoryDownloader(),
+            $this->artifact,
+            function (string $dir, string $ref): void {
+              $this->promptManager->renderAsInstalled($dir, $ref);
+            },
+          );
           return $version;
         },
         hint: fn(): string => sprintf('Downloading from "%s" repository at ref "%s"', $this->artifact->getRepo(), $this->artifact->getRef()),
@@ -262,7 +268,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
       return Command::FAILURE;
     }
 
-    $this->presenter->footer();
+    $this->presenter->footer($this->fileManager->getRegistryFile());
 
     $should_build = TRUE;
     $requested_build = (bool) $this->config->get(Config::BUILD_NOW);

.vortex/installer/src/Prompts/InstallerPresenter.php

@@ -7,6 +7,7 @@
 use DrevOps\VortexInstaller\Downloader\Artifact;
 use DrevOps\VortexInstaller\Prompts\Handlers\Starter;
 use DrevOps\VortexInstaller\Utils\Config;
+use DrevOps\VortexInstaller\Utils\File;
 use DrevOps\VortexInstaller\Utils\Strings;
 use DrevOps\VortexInstaller\Utils\Tui;
 use Symfony\Component\Process\ExecutableFinder;
@@ -122,13 +123,26 @@ public function header(Artifact $artifact, string $version): void {
     Tui::box($content, $title);
   }
 
-  public function footer(): void {
+  /**
+   * Display the footer after the installation finished.
+   *
+   * @param string|null $registry_file
+   *   Path of the registry of project changes the update replaced, or NULL
+   *   when the update replaced none.
+   */
+  public function footer(?string $registry_file = NULL): void {
     $output = '';
     $prefix = '  ';
 
     if ($this->config->isVortexProject()) {
       $title = 'Finished updating Vortex';
       $output .= 'Please review the changes and commit the required files.';
+
+      if ($registry_file !== NULL) {
+        $output .= PHP_EOL . PHP_EOL;
+        $output .= 'Project changes replaced by this update are recorded in:' . PHP_EOL;
+        $output .= $prefix . File::toRelative($registry_file, (string) $this->config->getDestination()) . PHP_EOL;
+      }
     }
     else {
       $title = 'Finished installing Vortex';

.vortex/installer/src/Prompts/PromptManager.php

@@ -72,6 +72,14 @@ class PromptManager {
    */
   protected array $responses = [];
 
+  /**
+   * Responses describing the destination as the handlers found it.
+   *
+   * Collected while the prompts run, so each value is the one discovery
+   * produced with the same preceding responses in context.
+   */
+  protected array $discoveredResponses = [];
+
   /**
    * Current response index.
    *
@@ -247,6 +255,40 @@ public function runPrompts(): void {
     // Filter out elements with numeric keys returned by intro() calls.
     $responses = array_filter($responses, fn($key): bool => !is_numeric($key), ARRAY_FILTER_USE_KEY);
 
+    if ($this->config->getNoInteraction()) {
+      Tui::output()->setVerbosity($original_verbosity);
+    }
+
+    $this->responses = $this->normalizeResponses($responses);
+
+    // A conditional prompt this run skips never reaches args(), so its handler
+    // is asked directly. Otherwise the answer describing the destination would
+    // be replaced by the one describing this run.
+    foreach ($this->handlers as $id => $handler) {
+      if (!isset($this->discoveredResponses[$id])) {
+        $discovered = $handler->discover();
+
+        if ($discovered !== NULL) {
+          $this->discoveredResponses[$id] = $discovered;
+        }
+      }
+    }
+
+    // Discovery covers only the handlers that read the destination, so the
+    // collected answers fill the rest.
+    $this->discoveredResponses = $this->normalizeResponses(array_replace($responses, $this->discoveredResponses));
+  }
+
+  /**
+   * Fold internal answers into the responses they qualify.
+   *
+   * @param array $responses
+   *   Raw responses keyed by handler ID.
+   *
+   * @return array
+   *   The responses with internal answers merged and removed.
+   */
+  protected function normalizeResponses(array $responses): array {
     if (isset($responses[Profile::id()]) && $responses[Profile::id()] === Profile::CUSTOM && isset($responses[ProfileCustom::id()])) {
       $responses[Profile::id()] = $responses[ProfileCustom::id()];
     }
@@ -270,11 +312,7 @@ public function runPrompts(): void {
       $responses[Starter::id()] = Starter::LOAD_DATABASE_DEMO;
     }
 
-    if ($this->config->getNoInteraction()) {
-      Tui::output()->setVerbosity($original_verbosity);
-    }
-
-    $this->responses = $responses;
+    return $responses;
   }
 
   /**
@@ -348,6 +386,31 @@ public function runProcessors(): void {
     File::runDirectoryTasks($this->config->get(Config::TMP));
   }
 
+  /**
+   * Render a template download as the destination has it installed.
+   *
+   * The answers come from discovery against the destination rather than from
+   * the choices this run collected, so the render reproduces the project's
+   * current configuration even where this run changes it. That is what makes
+   * the result comparable to the project's own files.
+   *
+   * @param string $dir
+   *   Directory holding an unprocessed template download.
+   * @param string $version
+   *   Version to stamp into the rendered content.
+   */
+  public function renderAsInstalled(string $dir, string $version): void {
+    $config = clone $this->config;
+    $config->set(Config::TMP, $dir, TRUE);
+    $config->set(Config::VERSION, $version, TRUE);
+
+    // Handlers bind to the directory they are constructed with, so rendering
+    // into a directory other than this run's staging copy needs its own set.
+    $manager = new self($config);
+    $manager->responses = $this->discoveredResponses;
+    $manager->runProcessors();
+  }
+
   /**
    * Run all post-build processors.
    *
@@ -659,6 +722,10 @@ protected function args(string $handler_class, mixed $default_override = NULL, a
     $default_from_prompts = $this->promptOverrides[$id] ?? NULL;
     $default_from_discovery = $handler->discover();
 
+    if ($default_from_discovery !== NULL) {
+      $this->discoveredResponses[$id] = $default_from_discovery;
+    }
+
     if ($default_from_prompts !== NULL) {
       $default = $default_from_prompts;
     }
@@ -703,6 +770,10 @@ protected function resolveOrPrompt(string $handler_id, array $r, callable $promp
         Tui::success($message);
       }
 
+      // A resolved value is read from the destination, so it stands in for
+      // discovery for handlers that never reach a prompt.
+      $this->discoveredResponses[$handler_id] = $resolved;
+
       return $resolved;
     }