3.05 Email Signature Automatizare si Branding

- AD prefill: 'Din cont' button pre-fills name + company from Authentik session
- Logo size slider: 50%-200% scale control in Stil & Aranjare section
- Promotional banner: configurable image+link below signature with preview
- US/SDT custom graphics: dedicated dash (US) and dot (SDT) decorative icons
  replacing Beletage's grey/accent slashes for company-specific branding

public/logos/sdt-dot-accent.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="11" height="7" viewBox="0 0 11 7">
+  <circle cx="5.5" cy="3.5" r="2.5" fill="#0182A1"/>
+</svg>

public/logos/sdt-dot-grey.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="11" height="11" viewBox="0 0 11 11">
+  <circle cx="5.5" cy="5.5" r="3" fill="#A7A9AA"/>
+</svg>

public/logos/us-dash-accent.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="11" height="7" viewBox="0 0 11 7">
+  <rect x="1" y="2.5" width="9" height="2" rx="1" fill="#345476"/>
+</svg>

public/logos/us-dash-grey.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="11" height="11" viewBox="0 0 11 11">
+  <rect x="1" y="4.5" width="9" height="2" rx="1" fill="#A7A9AA"/>
+</svg>