controller v0.265.0: R-634 cause fixed, held apps say so, OOM storm alarm, R-647 leftovers

R-634: a whole-box backup no longer stops/restarts a DEPLOYING app (the
measured cause of containers running under 'not deployed'); StopStack
and StartStack refuse a deploying stack for every caller.
R-625: held badge 'Stopped - restore needed', no Update button.
R-636: kernel oom_kill counter; 20+ in 30 min -> one app_oom_storm.
R-647: held error per reader, copy_holds key, two log wordings.

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

controller/internal/web/server.go

@@ -310,6 +310,9 @@ func (s *Server) loadTemplates() {
 		for name, fn := range s.localeFuncs(lang) {
 			funcs[name] = fn
 		}
+		for name, fn := range s.readerFuncs(lang, funcs) {
+			funcs[name] = fn
+		}
 		start := time.Now()
 		t, st, err := parseTemplateSet(b, lang, funcs)
 		took := time.Since(start)