R-518: backup button copy says local copy, one short stop, off-site at night (hu+en)

The 'Mentes most' hint and its confirm stated the v0.296.0 measurements
(about 6 min / 9 apps, about 8 min / 12 apps) and that the off-site copy in
the same run makes it longer. Since decision 156 the press makes the local
copy only and resumes the apps at its snapshot, so the copy now says: a
short stop of about 1-1.5 minutes (longer with more apps), the apps run
again while the copy finishes, the off-site copy follows with the next
nightly backup. Parity fixtures updated in place;
TestR518_BackupButtonStatesTheMeasuredDowntime ->
TestR518_BackupButtonStatesTheShortLocalOnlyStop (new copy on page AND in
confirm, old minutes gone, ASCII fragments).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/i18n/locales/en.json

@@ -194,7 +194,7 @@
   "backups.a_kijeloles_nem_sikerult": "The drive could not be assigned:",
   "backups.a_meghajto_kijelolve": "The drive is assigned.",
   "backups.a_meghajto_kijelolve_a_beallitas": "The drive is assigned. The setting takes effect after the host agent next restarts.",
-  "backups.a_mentes_alatt_az_alkalmazasok": "Every app stops for as long as the full system backup takes. That means minutes, not seconds: about 6 minutes on a box with 9 apps, about 8 minutes on a box with 12 — longer with more data, and longer when the off-site copy is made in the same run.",
+  "backups.a_mentes_alatt_az_alkalmazasok": "Every app stops briefly for the backup: about 1–1.5 minutes, longer with more apps. Then the apps run again while the copy finishes. This button makes the local copy; the off-site copy follows with the next nightly backup.",
   "backups.a_mentes_sikertelen": "The backup failed.",
   "backups.a_mentesek_egymas_utan_futnak": "The backups run one after the other: database backup, local copy, remote backup, then the full system backup.",
   "backups.a_rendszermentes_elkeszult": "The system backup is done.",
@@ -208,7 +208,7 @@
   "backups.beagyazott_db_k_a_kotetmentesben": "embedded databases, inside the volume backup",
   "backups.biztonsagi_mentes": "Backup",
   "backups.db_mentesek": "Database backups",
-  "backups.elinditod_a_teljes_rendszermentest_most": "Start the full system backup now? Every app stops for as long as the full system backup takes. That means minutes, not seconds: about 6 minutes on a box with 9 apps, about 8 minutes on a box with 12 — longer with more data, and longer when the off-site copy is made in the same run.",
+  "backups.elinditod_a_teljes_rendszermentest_most": "Start the full system backup now? Every app stops briefly for the backup: about 1–1.5 minutes, longer with more apps. Then the apps run again while the copy finishes. This button makes the local copy; the off-site copy follows with the next nightly backup.",
   "backups.esedekes": "Due",
   "backups.fajl": "{{$n := len .Backup.DumpFiles}}{{$n}} {{if eq $n 1}}file{{else}}files{{end}}",
   "backups.helyi_masolat": "Local copy: <strong>{{.BackupLegTier2}}</strong>",