v0.317.0: a second copy counts only on a proven different disk; the no-drive install speaks in words (felhom.eu architecture/16, build A)

Tier-2 and the one-copy notice ask the host agent (POST /disks/same-disk, agent 0.157.0): different +
proven -> made and counted; same disk -> not made (D1); unknown (VM, hidden USB serial) -> made, not
counted, the row says why (D2); a NAS never counts and no longer hides the notice (R-1075). An older
agent keeps the st_dev rule, logged once. D4: a data-folder or media app on a box with no drive is
refused in words with a link to the drives page (R-1068's raw-error half). MinAgent 0.157.0.

Claude-Session: https://claude.ai/code/session_012qRErfCoiTkvDK9N5XHbzb

controller/internal/web/templates/backups_apps.html

@@ -283,6 +283,7 @@
                              not render as a plain fresh copy. The status line above is about the RUN;
                              this one is about the PACKAGE, and after a preserved leg they differ. */}}
                         {{if .Tier2UnitStaleNotice}}<span class="layer-reason" style="color:var(--warn);opacity:.9">{{.Tier2UnitStaleNotice}}</span>{{end}}
+                        {{if .Tier2UnprovenNotice}}<span class="layer-reason" style="color:var(--warn);opacity:.9">{{.Tier2UnprovenNotice}}</span>{{end}}
                         <span class="tier-contents">{{.Tier23Contents}}</span>
                         <span class="tier-browsable" title="{{T "backups_apps.a_mentes_bongeszheto_fajlrendszerben"}}"><svg class="ico ico-sm"><use href="#i-file-text"/></svg></span>
                         <div class="layer-actions">