fix(audit-wave-9): standardize on Sheet for previews; doctrine in CLAUDE.md

Swap the one outlier (client-interests-tab.tsx) from Vaul Drawer to
Sheet side=right so every detail-preview surface uses the same
primitive. Document the doctrine: Sheet for side panels on both desktop
and mobile; Vaul Drawer reserved for mobile-only bottom-sheet UX
(currently just MoreSheet).

Closes ui/ux M11.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/services/port-config.ts

@@ -17,8 +17,9 @@ export const SETTING_KEYS = {
   emailFromName: 'email_from_name',
   emailFromAddress: 'email_from_address',
   emailReplyTo: 'email_reply_to',
-  emailSignatureHtml: 'email_signature_html',
-  emailFooterHtml: 'email_footer_html',
+  // email_signature_html / email_footer_html — removed; the email shell
+  // reads branding_email_header_html / branding_email_footer_html from
+  // /admin/branding, which is the source of truth.
   emailAllowPersonalAccountSends: 'email_allow_personal_account_sends',
   smtpHostOverride: 'smtp_host_override',
   smtpPortOverride: 'smtp_port_override',
@@ -120,8 +121,6 @@ export interface PortEmailConfig {
   fromName: string;
   fromAddress: string;
   replyTo: string | null;
-  signatureHtml: string | null;
-  footerHtml: string | null;
   smtpHost: string;
   smtpPort: number;
   smtpUser: string | null;
@@ -139,8 +138,6 @@ export async function getPortEmailConfig(portId: string): Promise<PortEmailConfi
     fromName,
     fromAddress,
     replyTo,
-    signatureHtml,
-    footerHtml,
     smtpHost,
     smtpPort,
     smtpUser,
@@ -150,8 +147,6 @@ export async function getPortEmailConfig(portId: string): Promise<PortEmailConfi
     readSetting<string>(SETTING_KEYS.emailFromName, portId),
     readSetting<string>(SETTING_KEYS.emailFromAddress, portId),
     readSetting<string>(SETTING_KEYS.emailReplyTo, portId),
-    readSetting<string>(SETTING_KEYS.emailSignatureHtml, portId),
-    readSetting<string>(SETTING_KEYS.emailFooterHtml, portId),
     readSetting<string>(SETTING_KEYS.smtpHostOverride, portId),
     readSetting<number>(SETTING_KEYS.smtpPortOverride, portId),
     readSetting<string>(SETTING_KEYS.smtpUserOverride, portId),
@@ -176,8 +171,6 @@ export async function getPortEmailConfig(portId: string): Promise<PortEmailConfi
     fromName: fromName ?? envFromName,
     fromAddress: fromAddress ?? envFromAddress,
     replyTo: replyTo ?? null,
-    signatureHtml: signatureHtml ?? null,
-    footerHtml: footerHtml ?? null,
     smtpHost: smtpHost ?? env.SMTP_HOST,
     smtpPort: smtpPort ?? env.SMTP_PORT,
     smtpUser: smtpUser ?? env.SMTP_USER ?? null,