Feature/saajan persona (#3)

* feat: add template based email content (html + plaintext fallback)

* feat: init saajan component

* feat: add aesthetic noise background and implement Saajan component in register and login

* feat: add post seal modal for vault

* refactor: add proper props interfaces

* refactor: expose props on ui components

* feat: add ssajan in lots of flows

* fix: remove render test with no value and add aria helper for btn identification

* refactor: update email notification to account for proper arguments

* refactor:  refactor E2E auth helper and mail parsing logic

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Co-authored-by: ramvignesh-b <ramvignesh-b@github.com>

frontend/e2e/letter.spec.ts

@@ -185,7 +185,7 @@ test.describe("Letter Drafting (Real Backend)", () => {
     await expect(page.getByText(/your letter is sealed/i)).toBeVisible({
       timeout: 10000,
     });
-    await page.getByRole("button", { name: /keep it/i }).click();
+    await page.getByRole("button", { name: /keep it to myself/i }).click();
 
     // Open "Kept" section - search for the section with id='kept' and click its toggle button
     logger.info(">> [Drawer] Opening Kept section...");