config: a workstation block, dropped when it names no address (V-485)

Health defaults to the supervisor's /health rather than llama-server's,
because mavgpud is what answers 503 while the card is held.

internal/config/config_test.go

@@ -413,3 +413,56 @@ func TestNormaliseFillsKiwixDefaults(t *testing.T) {
 		t.Error("rewrite: false was not honoured")
 	}
 }
+
+// A workstation with no address is not a workstation. The unconfigured deploy
+// must be indistinguishable from today, so the block is dropped rather than
+// left to fail one probe at a time.
+func TestNormaliseDropsAddresslessWorkstation(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		in   *WorkstationConfig
+	}{
+		{"no url", &WorkstationConfig{Probe: Duration(time.Second)}},
+		{"blank url", &WorkstationConfig{URL: "   "}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			c := &Config{Workstation: tc.in}
+			c.applyDefaults()
+			if c.Workstation != nil {
+				t.Errorf("kept an unusable workstation block: %+v", c.Workstation)
+			}
+		})
+	}
+}
+
+// The health endpoint defaults to the supervisor's, not llama-server's: mavgpud
+// answers 503 while the card is held, and that refusal is the whole signal.
+func TestNormaliseFillsWorkstationDefaults(t *testing.T) {
+	c := &Config{Workstation: &WorkstationConfig{URL: "http://192.168.1.105:8080/"}}
+	c.applyDefaults()
+	if c.Workstation == nil {
+		t.Fatal("dropped a usable workstation block")
+	}
+	if got, want := c.Workstation.Health, "http://192.168.1.105:8080/health"; got != want {
+		t.Errorf("Health = %q, want %q", got, want)
+	}
+	if time.Duration(c.Workstation.Probe) != DefaultWorkstationProbe {
+		t.Errorf("Probe = %s, want %s", time.Duration(c.Workstation.Probe), DefaultWorkstationProbe)
+	}
+	if time.Duration(c.Workstation.Timeout) != DefaultWorkstationTimeout {
+		t.Errorf("Timeout = %s, want %s", time.Duration(c.Workstation.Timeout), DefaultWorkstationTimeout)
+	}
+}
+
+// An explicit health URL is left alone: the supervisor may sit behind something
+// that does not put /health at the root.
+func TestNormaliseKeepsExplicitWorkstationHealth(t *testing.T) {
+	c := &Config{Workstation: &WorkstationConfig{
+		URL:    "http://192.168.1.105:8080",
+		Health: "http://192.168.1.105:9000/ready",
+	}}
+	c.applyDefaults()
+	if got, want := c.Workstation.Health, "http://192.168.1.105:9000/ready"; got != want {
+		t.Errorf("Health = %q, want %q", got, want)
+	}
+}