test: close coverage gaps for timmy_serve CLI, voice_enhanced, WebSocket, and swarm live page

- Add 8 tests for timmy_serve/cli.py (start, invoice, status commands)
  covering default args, custom args, and output validation
- Add 8 tests for voice_enhanced route covering all intent types
  (status, help, swarm, voice, chat fallback) plus error handling
- Add 17 tests for websocket/handler.py covering broadcast to
  multiple clients, dead connection cleanup, history trimming,
  connect/disconnect, and all convenience broadcast methods
- Add 4 tests for the new GET /swarm/live page route

Total new tests: 37

tests/test_timmy_serve_cli.py

@@ -0,0 +1,65 @@
+"""Tests for timmy_serve/cli.py — Serve-mode CLI commands."""
+
+from typer.testing import CliRunner
+
+from timmy_serve.cli import app
+
+runner = CliRunner()
+
+
+class TestStartCommand:
+    def test_start_default_port(self):
+        result = runner.invoke(app, ["start"])
+        assert result.exit_code == 0
+        assert "8402" in result.output
+        assert "L402 payment proxy active" in result.output
+
+    def test_start_custom_port(self):
+        result = runner.invoke(app, ["start", "--port", "9000"])
+        assert result.exit_code == 0
+        assert "9000" in result.output
+
+    def test_start_custom_host(self):
+        result = runner.invoke(app, ["start", "--host", "127.0.0.1"])
+        assert result.exit_code == 0
+        assert "127.0.0.1" in result.output
+
+    def test_start_shows_endpoints(self):
+        result = runner.invoke(app, ["start"])
+        assert "/serve/chat" in result.output
+        assert "/serve/invoice" in result.output
+        assert "/serve/status" in result.output
+
+
+class TestInvoiceCommand:
+    def test_invoice_default_amount(self):
+        result = runner.invoke(app, ["invoice"])
+        assert result.exit_code == 0
+        assert "100 sats" in result.output
+        assert "API access" in result.output
+
+    def test_invoice_custom_amount(self):
+        result = runner.invoke(app, ["invoice", "--amount", "500"])
+        assert result.exit_code == 0
+        assert "500 sats" in result.output
+
+    def test_invoice_custom_memo(self):
+        result = runner.invoke(app, ["invoice", "--memo", "Test payment"])
+        assert result.exit_code == 0
+        assert "Test payment" in result.output
+
+    def test_invoice_shows_payment_hash(self):
+        result = runner.invoke(app, ["invoice"])
+        assert "Payment hash:" in result.output
+        assert "Pay request:" in result.output
+
+
+class TestStatusCommand:
+    def test_status_runs_successfully(self):
+        result = runner.invoke(app, ["status"])
+        assert result.exit_code == 0
+        assert "Timmy Serve" in result.output
+        assert "Total invoices:" in result.output
+        assert "Settled:" in result.output
+        assert "Total earned:" in result.output
+        assert "sats" in result.output