R-575: the overcommit warning follows the reader's language

memoryVerdict returns the warning's bundle KEY (KeyMemoryOvercommitWarning)
and DeployStack hands it on; the API renders it per request
(deployWarningData). msgHU, whose only use this was, is gone.

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

controller/internal/stacks/r575_overcommit_key_test.go

@@ -0,0 +1,24 @@
+package stacks
+
+import (
+	"io"
+	"log"
+	"testing"
+
+	"gitea.dooplex.hu/admin/felhom-controller/internal/config"
+)
+
+// R-575: the soft overcommit warning leaves memoryVerdict as a bundle KEY, never as Hungarian text, so
+// the API can render it in the reader's language. PATH is emptied so the memory reading can never fall
+// through to `docker info` on the host running the test.
+func TestR575_OvercommitWarningIsAKey(t *testing.T) {
+	t.Setenv("PATH", "")
+	m := &Manager{cfg: &config.Config{}, logger: log.New(io.Discard, "", 0), stacks: map[string]*Stack{}}
+	refusal, warning := m.memoryVerdict(0, 1<<30, 0, 0) // a limit no machine has: overcommit, no hard block
+	if refusal != nil {
+		t.Fatalf("no request -> no refusal, got %v", refusal)
+	}
+	if warning != KeyMemoryOvercommitWarning {
+		t.Fatalf("warning = %q, want the bundle key %q", warning, KeyMemoryOvercommitWarning)
+	}
+}