feat(email-signature): wire SDT/US branding, address selector, color palettes, improved preview

- Per-company branding for Urban Switch and Studii de Teren (logos, websites, mottos)
- Beletage address selector (Str. Unirii vs Str. G-ral Eremia Grigorescu)
- Company-specific color palettes in configurator
- Scrollable preview with multi-level zoom (0.75x to 2.5x)
- Address override support in signature config

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/modules/email-signature/services/signature-builder.ts

@@ -14,6 +14,7 @@ export function formatPhone(raw: string): { display: string; link: string } {
 
 export function generateSignatureHtml(config: SignatureConfig): string {
   const branding = getBranding(config.company);
+  const address = config.addressOverride ?? branding.address;
   const { display: phone, link: phoneLink } = formatPhone(config.phone);
   const images = config.useSvg
     ? { logo: branding.logo.svg, greySlash: branding.slashGrey.svg, accentSlash: branding.slashAccent.svg }
@@ -71,7 +72,7 @@ export function generateSignatureHtml(config: SignatureConfig): string {
               </td>
               <td width="${spacerWidth}" style="width:${spacerWidth}px; font-size:0; line-height:0;"></td>
               <td style="vertical-align:top; padding:0 0 0 ${textPaddingLeft}px;">
-                <span style="color:${colors.address}; text-decoration:none;">${branding.address.join('<br>')}</span>
+                <span style="color:${colors.address}; text-decoration:none;">${address.join('<br>')}</span>
               </td>
             </tr>
             <tr>