i18n+ui: backlog quick-wins sweep (F-32/33/34/35/44/45/47/50/58/62 + 2 mediums)

Cluster of the v1.4.21 carry-over items that each landed in ≤5 LOC.

- F-32 — drop the duplicate help paragraph beneath the dashboard
  settings header; the page-level description already covers it
- F-33 / F-34 — replace `&` with "and"/"und" in the measurements and
  mood subtitles
- F-35 — unify the test-notification button label
  (notificationTestSend) with the user-facing notificationStatus.sendTest
- F-44 — drop the `LOKI_ENDPOINT` env-var name from the user-facing
  monitoring help text; reads as "Loki integration" instead
- F-45 — admin/users table column reads "Name" instead of repeating
  the page title "Users"
- F-47 — /notifications event-matrix first column reads "Event" instead
  of repeating the page title "Notifications" — new notifications.eventColumn key
- F-50 — soften every DE error-toast "Bitte erneut versuchen" to
  "Bitte versuche es erneut", matching the friendlier tone we already
  use in the Coach error path
- F-58 — admin/reminders section header swaps Clock for Bell so the
  card icon matches the admin-shell nav tile
- F-62 — DE dashboard `greetingSalutation` reads "Hallo, {name}"
  instead of the English "Hi, {name}"
- D-CR-M-03 — formatTokenName regex broadens to non-Z ISO offsets so a
  `+02:00` timestamp suffix renders as the locale-aware chunk like a
  `Z` suffix already does
- D-DSGN-M-04 — moodLog "Copy" button uses common.copy instead of
  stripping the `!` off common.copied

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

src/app/notifications/page.tsx

@@ -191,7 +191,7 @@ export default function NotificationsPage() {
           <thead>
             <tr className="border-border border-b">
               <th className="text-muted-foreground px-4 py-3 text-left text-xs font-medium tracking-wider uppercase">
-                {t("notifications.title")}
+                {t("notifications.eventColumn")}
               </th>
               {activeChannels.map((ch) => (
                 <th