feat(stepper,updater): add progress-aware stepper flows and updater countdown states

readme.md

@@ -1508,18 +1508,33 @@ const layer = await DeesWindowLayer.createAndShow({
 ### Navigation Components
 
 #### `DeesStepper`
-Multi-step navigation component for guided user flows.
+Multi-step navigation component for guided user flows, including optional auto-advancing progress steps that can render `dees-progressbar` status output between form steps.
 
 ```typescript
 <dees-stepper
   .steps=${[
-    { key: 'personal', label: 'Personal Info', content: html`<div>Form 1</div>` },
-    { key: 'address', label: 'Address', content: html`<div>Form 2</div>` },
-    { key: 'confirm', label: 'Confirmation', content: html`<div>Review</div>` }
+    {
+      title: 'Account Setup',
+      content: html`<dees-form>...</dees-form>`,
+      menuOptions: [{ name: 'Continue', action: async (stepper) => stepper?.goNext() }]
+    },
+    {
+      title: 'Provision Workspace',
+      content: html`<p>Preparing your environment...</p>`,
+      progressStep: {
+        label: 'Workspace setup',
+        indeterminate: true,
+        statusRows: 4,
+        terminalLines: ['Allocating workspace']
+      },
+      validationFunc: async (stepper, _element, signal) => {
+        stepper.updateProgressStep({ percentage: 35, statusText: 'Installing dependencies...' });
+        stepper.appendProgressStepLine('Installing dependencies');
+        if (signal?.aborted) return;
+        stepper.updateProgressStep({ percentage: 100, indeterminate: false, statusText: 'Workspace ready.' });
+      }
+    }
   ]}
-  currentStep="personal"
-  @step-change=${handleStepChange}
-  @complete=${handleComplete}
 ></dees-stepper>
 ```
 
@@ -1580,6 +1595,33 @@ Theme provider component that wraps children and provides CSS custom properties
 - Works with dark/light mode
 - Overrides cascade to all child components
 
+#### `DeesUpdater`
+Updater controller that opens a non-cancelable `dees-stepper` flow with a progress step and a ready step.
+
+```typescript
+const updater = await DeesUpdater.createAndShow({
+  currentVersion: '3.79.0',
+  updatedVersion: '3.80.0',
+  moreInfoUrl: 'https://code.foss.global/design.estate/dees-catalog',
+  changelogUrl: 'https://code.foss.global/design.estate/dees-catalog/-/blob/main/changelog.md',
+  successAction: 'reload',
+  successDelayMs: 10000,
+});
+
+updater.updateProgress({
+  percentage: 35,
+  statusText: 'Downloading signed bundle...',
+  terminalLines: ['Checking release manifest', 'Downloading signed bundle']
+});
+
+updater.appendProgressLine('Verifying checksum');
+updater.updateProgress({ percentage: 72, statusText: 'Verifying checksum...' });
+
+await updater.markUpdateReady();
+```
+
+After `markUpdateReady()`, the updater switches to a second countdown step with a determinate progress bar and runs the configured success action when the timer reaches zero.
+
 ---
 
 ### Workspace / IDE Components 💻