Final-pass polish: support contact UX, audit tooltip, doc refresh

Support teams: contact management moved from a row expander to a modal
(Contacts (N) button per team); application detail Support card and the
modal show Email (mailto) and Teams chat buttons for contacts with an
SSO, derived as sso@ + a new contact_email_domain site setting
(default geaerospace.com, blank hides the buttons).

Audit log: hovering a user SSO shows the full name, resolved
best-effort from the employee directory in either mode.

Docs/hygiene from a standards review: CLAUDE.md active-state,
CONTRACT-STABILITY.md and README brought to contract 0.10.0 / 11
plugins / migration head 7d22; get_asset_panels endpoint path fixed in
the hook docstring; leftover debug console.logs removed.

781 tests pass; contacts modal, action-button hrefs, and the audit
tooltip verified live.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/utils/siteSettings.js

@@ -120,6 +120,16 @@ export async function getPrinterHostnameTemplate() {
   return getSetting('printer_hostname_template', 'Printer-{ip}.printer.geaerospace.net')
 }
 
+// Email domain appended to a contact SSO to build email/Teams links
+// (sso@domain). Unset falls back to geaerospace.com; an explicit blank value
+// means "disable contact action buttons", so read the raw setting rather than
+// getSetting (which swaps '' for the fallback).
+export async function getContactEmailDomain() {
+  const settings = await loadSettings()
+  const value = settings['contact_email_domain']
+  return (value === undefined || value === null) ? 'geaerospace.com' : value
+}
+
 // Apply per-site favicon + brand color at bootstrap. Empty settings keep the
 // shipped defaults. Do not touch the style.css palette here.
 export async function applyBranding() {