feat: configurable stop grace period for applications

Adds stop_grace_period to application settings (seconds, 1-3600, default 30).
Used in place of the hardcoded docker stop -t 30 in the four places that
stop application containers: rolling update shutdown, manual stop, stop on
another server, and preview deployment stop.

Non-positive values fall back to the default via ($val > 0) ? $val : default,
with tests covering 0 and -10 so the cast does not blow up if a bad value
ever lands in the db.

Picks up Jack Coy's work from #7125 which went dormant. His commits are
squashed here with credit below.

Co-authored-by: Jack Coy <jackman3000@gmail.com>

app/Livewire/Project/Application/Advanced.php

@@ -61,6 +61,9 @@ class Advanced extends Component
     #[Validate(['string', 'nullable'])]
     public ?string $gpuOptions = null;
 
+    #[Validate(['string', 'nullable'])]
+    public ?string $stopGracePeriod = null;
+
     #[Validate(['boolean'])]
     public bool $isBuildServerEnabled = false;
 
@@ -145,6 +148,10 @@ class Advanced extends Component
             $this->injectBuildArgsToDockerfile = $this->application->settings->inject_build_args_to_dockerfile ?? true;
             $this->includeSourceCommitInBuild = $this->application->settings->include_source_commit_in_build ?? false;
         }
+
+        // Load stop_grace_period separately since it has its own save handler
+        // Convert null to empty string to prevent dirty detection issues
+        $this->stopGracePeriod = $this->application->settings->stop_grace_period ?? '';
     }
 
     private function resetDefaultLabels()
@@ -252,6 +259,34 @@ class Advanced extends Component
         }
     }
 
+    public function saveStopGracePeriod()
+    {
+        try {
+            $this->authorize('update', $this->application);
+
+            // Convert empty string to null, otherwise cast to integer
+            $value = ($this->stopGracePeriod === '' || $this->stopGracePeriod === null)
+                ? null
+                : (int) $this->stopGracePeriod;
+
+            // Validate the integer value
+            if ($value !== null && ($value < 1 || $value > 3600)) {
+                $this->dispatch('error', 'Stop grace period must be between 1 and 3600 seconds.');
+
+                return;
+            }
+
+            // Save to model
+            $this->application->settings->stop_grace_period = $value;
+            $this->application->settings->save();
+
+            // User feedback
+            $this->dispatch('success', 'Stop grace period updated.');
+        } catch (\Throwable $e) {
+            return handleError($e, $this);
+        }
+    }
+
     public function render()
     {
         return view('livewire.project.application.advanced');