style(backup): shorten the BACKUP_STRATEGY tooltip to one practical sentence

The advanced field was carrying a four-clause explanation walking through
"quiesce", "live dump", "stop fallback", and the live-option eligibility
rules — useful background for engineers, overwhelming as a hover tooltip
for the typical user picking from the dropdown.

New tooltip:
  "How the app is prepared before each backup. Automatic is recommended;
   pick Live only if you need zero downtime."

Two lines, plain language, points at the right default. The dropdown's
own labels (Automatic (recommended) / Stop→snapshot→start / Pause→snapshot
→unpause / Live — no downtime) carry the technical specifics; the
tooltip no longer has to.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>

scripts/webui/data/generators/categories/webui_create_app_field_mappings.sh

@@ -163,7 +163,7 @@ PORTEOF
       "category": "advanced",
       "label": "Backup Strategy",
       "type": "select",
-      "tooltip": "How this app is quiesced before its backup snapshot. Automatic picks the safest zero-downtime method available and falls back to stopping the app if a live dump ever fails. The Live option appears only for apps that can be backed up consistently without stopping (a database we can dump, or a static app marked live-safe).",
+      "tooltip": "How the app is prepared before each backup. Automatic is recommended; pick Live only if you need zero downtime.",
       "advanced": true,
       "options": [
         {"value": "auto", "label": "Automatic (recommended)"},