refactor: Phase 3 — reorganize tests into module-mirroring subdirectories

Move 97 test files from flat tests/ into 13 subdirectories:
  tests/dashboard/   (8 files — routes, mobile, mission control)
  tests/swarm/       (17 files — coordinator, docker, routing, tasks)
  tests/timmy/       (12 files — agent, backends, CLI, tools)
  tests/self_coding/  (14 files — git safety, indexer, self-modify)
  tests/lightning/   (3 files — L402, LND, interface)
  tests/creative/    (8 files — assembler, director, image/music/video)
  tests/integrations/ (10 files — chat bridge, telegram, voice, websocket)
  tests/mcp/         (4 files — bootstrap, discovery, executor)
  tests/spark/       (3 files — engine, tools, events)
  tests/hands/       (3 files — registry, oracle, phase5)
  tests/scripture/   (1 file)
  tests/infrastructure/ (3 files — router cascade, API)
  tests/security/    (3 files — XSS, regression)

Fix Path(__file__) reference in test_mobile_scenarios.py for new depth.
Add __init__.py to all test subdirectories.

Tests: 1503 passed, 9 failed (pre-existing), 53 errors (pre-existing)

https://claude.ai/code/session_019oMFNvD8uSGSSmBMGkBfQN

tests/lightning/test_l402_proxy.py

@@ -0,0 +1,110 @@
+"""Tests for the L402 proxy and payment handler."""
+
+import hashlib
+
+import pytest
+
+
+# ── Payment Handler ──────────────────────────────────────────────────────────
+
+def test_create_invoice():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    invoice = handler.create_invoice(100, "test payment")
+    assert invoice.amount_sats == 100
+    assert invoice.memo == "test payment"
+    assert invoice.payment_hash is not None
+    assert invoice.payment_request.startswith("lnbc")
+
+
+def test_check_payment_mock_auto_settles():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    invoice = handler.create_invoice(50, "auto settle")
+    assert handler.check_payment(invoice.payment_hash) is True
+
+
+def test_check_payment_nonexistent():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    assert handler.check_payment("nonexistent-hash") is False
+
+
+def test_settle_invoice_with_preimage():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    invoice = handler.create_invoice(75, "preimage test")
+    invoice.settled = False  # Reset for manual settlement
+    assert handler.settle_invoice(invoice.payment_hash, invoice.preimage) is True
+    assert invoice.settled is True
+
+
+def test_settle_invoice_wrong_preimage():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    invoice = handler.create_invoice(75, "wrong preimage")
+    invoice.settled = False
+    assert handler.settle_invoice(invoice.payment_hash, "0" * 64) is False
+
+
+def test_list_invoices():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    handler.create_invoice(10, "a")
+    handler.create_invoice(20, "b")
+    assert len(handler.list_invoices()) == 2
+
+
+def test_list_invoices_settled_only():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    inv = handler.create_invoice(10, "settle me")
+    handler.check_payment(inv.payment_hash)  # auto-settles in mock
+    settled = handler.list_invoices(settled_only=True)
+    assert len(settled) >= 1
+
+
+def test_get_invoice():
+    from timmy_serve.payment_handler import PaymentHandler
+    handler = PaymentHandler()
+    inv = handler.create_invoice(100, "get me")
+    found = handler.get_invoice(inv.payment_hash)
+    assert found is not None
+    assert found.amount_sats == 100
+
+
+# ── L402 Proxy ───────────────────────────────────────────────────────────────
+
+def test_create_l402_challenge():
+    from timmy_serve.l402_proxy import create_l402_challenge
+    challenge = create_l402_challenge(100, "API access")
+    assert "macaroon" in challenge
+    assert "invoice" in challenge
+    assert "payment_hash" in challenge
+
+
+def test_verify_l402_token_valid():
+    from timmy_serve.l402_proxy import create_l402_challenge, verify_l402_token
+    challenge = create_l402_challenge(50, "verify test")
+    # In mock mode, payment auto-settles
+    assert verify_l402_token(challenge["macaroon"]) is True
+
+
+def test_verify_l402_token_invalid_format():
+    from timmy_serve.l402_proxy import verify_l402_token
+    assert verify_l402_token("not-a-valid-token") is False
+
+
+def test_macaroon_roundtrip():
+    from timmy_serve.l402_proxy import Macaroon
+    mac = Macaroon(identifier="test-id", signature="test-sig")
+    serialized = mac.serialize()
+    restored = Macaroon.deserialize(serialized)
+    assert restored is not None
+    assert restored.identifier == "test-id"
+    assert restored.signature == "test-sig"
+
+
+def test_macaroon_deserialize_invalid():
+    from timmy_serve.l402_proxy import Macaroon
+    assert Macaroon.deserialize("garbage") is None