Read and control the house through Home Assistant (#256)

A `smarthome` block points Maven at a Home Assistant instance. She reads its
entity states to answer "что включено дома?", and every controllable device
becomes a PROPOSED row in the existing act allowlist — cmd
["smarthome",<entity_id>,<service>], scope smarthome:<domain> — so nothing new
had to be invented for the mutating half. ProposeTool/EnableTool/DisableTool,
tool.Matcher and the confirm turn are untouched; one branch in Executor.Exec
routes such a row to the client instead of exec, and "smarthome" is never run as
a binary. This is the same trick overnight/mcp-tools used for #251, on purpose.

Discovery only ever PROPOSES, and every control row is destructive=true: there
is no read-only way to turn the heating off, so flipping something in his flat
always costs a confirm turn and always had to be enabled by hand on /tools,
behind step-up.

The entity and the service come from the row he enabled, never from the
utterance — Exec drops the spoken tail for a house row. A router that misheard
can pick the wrong lamp; it cannot compose a target of its own. The service is
checked against the domain's table on the way out too, so a hand-edited cmd
column cannot reach an arbitrary Home Assistant service. set_brightness and
set_temperature are deliberately absent: a spoken number the router got wrong is
a wrong act on real hardware, and on/off is the whole of what a voice turn can
defend.

The read side is a query source ("home", before calendar and the recall passes)
so "что нового дома?" is not answered from an old note. Its matcher needs a
house marker plus an ask plus a device word and bails out on weather wording,
because "какая температура на улице?" belongs to the weather source.

Off unless configured: the block is dark without "enabled": true, and
applyDefaults normalises a disabled block to nil so "off" stays in one place.
deploy/mavend.json carries it disabled, with the token as ${HA_TOKEN}.

NOT shipped, and not faked: MQTT / Zigbee2MQTT (plan steps 2 and 5) and the
sensor-to-fact and presence-probe pipelines. There is no broker and no Home
Assistant anywhere on this network — 8123 and 1883 are closed on every host in
192.168.1.0/24 — the module tree is vendored so a paho dependency cannot be
added offline, and Home Assistant already fronts Zigbee2MQTT where it exists.
Writing a sensor pipeline with no sensor to test it against would be a guess.

Vikunja #256

internal/tool/tool_test.go

@@ -185,3 +185,80 @@ func TestExecMCPRowWithoutCallerRefuses(t *testing.T) {
 		t.Fatal(`"mcp" must never be run as a binary`)
 	}
 }
+
+// fakeHome records what the executor asked the house to do.
+type fakeHome struct {
+	entity, service string
+	calls           int
+}
+
+func (f *fakeHome) CallService(_ context.Context, entityID, service string) (string, error) {
+	f.calls++
+	f.entity, f.service = entityID, service
+	return "готово", nil
+}
+
+// A house row goes through the same allowlist and the same confirm turn as any
+// other act, and it is never exec'd as a binary (Vikunja #256).
+func TestExecSmartHomeRow(t *testing.T) {
+	api := fakeAPI{tools: map[string]ipc.Tool{
+		"home_light_x_off": {
+			Name: "home_light_x_off", Scope: "smarthome:light",
+			Cmd: []string{"smarthome", "light.x", "turn_off"}, Destructive: true, Status: "enabled",
+		},
+		"home_draft": {
+			Name: "home_draft", Scope: "smarthome:light",
+			Cmd: []string{"smarthome", "light.y", "turn_on"}, Destructive: true, Status: "proposed",
+		},
+	}}
+	ran := false
+	newExec := func(h HomeCaller) *Executor {
+		e := NewExecutor(api, time.Second)
+		e.run = func(context.Context, []string) (string, error) { ran = true; return "", nil }
+		if h != nil {
+			e = e.WithHome(h)
+		}
+		return e
+	}
+
+	// No house configured ⇒ the row refuses rather than being exec'd.
+	if _, err := newExec(nil).Exec(context.Background(), "home_light_x_off", nil, true); !errors.Is(err, ErrNotEnabled) {
+		t.Fatalf("unconfigured house: err = %v, want ErrNotEnabled", err)
+	}
+	if ran {
+		t.Fatal(`"smarthome" was run as a binary`)
+	}
+
+	// Configured, but not confirmed ⇒ the confirm turn, before any call.
+	fh := &fakeHome{}
+	if _, err := newExec(fh).Exec(context.Background(), "home_light_x_off", nil, false); !errors.Is(err, ErrNeedsConfirm) {
+		t.Fatalf("err = %v, want ErrNeedsConfirm", err)
+	}
+	if fh.calls != 0 {
+		t.Fatal("an unconfirmed house act reached the house")
+	}
+
+	// A merely proposed row never runs, confirmed or not.
+	if _, err := newExec(fh).Exec(context.Background(), "home_draft", nil, true); !errors.Is(err, ErrNotEnabled) {
+		t.Fatalf("proposed row: err = %v, want ErrNotEnabled", err)
+	}
+	if fh.calls != 0 {
+		t.Fatal("a proposed house row reached the house")
+	}
+
+	// Confirmed ⇒ the service call, with the entity from the ROW and the
+	// spoken tail dropped.
+	out, err := newExec(fh).Exec(context.Background(), "home_light_x_off", []string{"light.somewhere_else"}, true)
+	if err != nil {
+		t.Fatalf("Exec: %v", err)
+	}
+	if out != "готово" {
+		t.Errorf("out = %q", out)
+	}
+	if fh.entity != "light.x" || fh.service != "turn_off" {
+		t.Errorf("called %s/%s: the target must come from the enabled row, never from the utterance", fh.entity, fh.service)
+	}
+	if ran {
+		t.Fatal(`"smarthome" was run as a binary`)
+	}
+}