Deliver BAT-002: slot-core daemon + HTTP intent API + PostgreSQL

Implement REQ-005~009 (dcy-002 slice 1) as an onion stack on top of the
BAT-001 pure domain:
- application: IntentService (admission + single-writer transition +
  intent_id idempotency via durable intent_log)
- adapters/persistence: PostgreSQLSlotRepository + PostgreSQLIntentStore +
  trex-core-owned migrations (daily_slot per Appendix A, daily_symbol_entries,
  slot_transition_log, intent_log) + in-memory intent store
- adapters/api: FastAPI /v1 (healthz, intents/buy|sell|{id}, slots, capacity)
- runtime: trex-core-daemon entrypoint with lifespan migrate+preallocate

Verification (against local PostgreSQL 18): 74 passed, ruff clean, domain
import sweep shows zero web/db deps (NFR-1), 20-thread concurrency admits
exactly the idle count (NFR-2), idempotent resubmit causes no double
transition (NFR-3), EXPECTED_SLOT_FIELDS<->information_schema drift test
(realizes dcy-001 OQ-2's deferred DB-side check), and a daemon E2E smoke.

Align all four baseline docs to the new daemon/API/persistence layers.
BAT-002 -> release-candidate; REQ-005~009 -> Implemented. Full async outbox,
broker execution, safety floor, and strategy daemons remain deferred to a
follow-up Discovery.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/adapters/api/test_intent_api.py

@@ -0,0 +1,112 @@
+"""HTTP /v1 API tests via in-memory adapters (REQ-005/007/008).
+
+No PostgreSQL needed: the app is wired with the in-memory slot repo + intent
+store, exercising the full request → admission → transition → response path.
+"""
+from __future__ import annotations
+
+from datetime import date
+
+import pytest
+from fastapi.testclient import TestClient
+
+from trex_core.adapters.api.app import create_app
+from trex_core.adapters.persistence.in_memory_intent_store import InMemoryIntentStore
+from trex_core.application.intents import IntentService
+from trex_core.domain.slot import SlotService, SlotState
+from trex_core.domain.slot.in_memory_repository import InMemorySlotRepository
+
+DAY = date(2026, 6, 3)
+
+
+@pytest.fixture
+def ctx():
+    repo = InMemorySlotRepository()
+    svc = SlotService(repo)
+    intents = IntentService(svc, repo, InMemoryIntentStore())
+    svc.preallocate_daily_slots(DAY, 3)
+    app = create_app(
+        slot_service=svc, slot_repo=repo, intent_service=intents, default_total_slots=3
+    )
+    return repo, svc, intents, TestClient(app)
+
+
+def _buy(client, intent_id, symbol="005930"):
+    return client.post(
+        "/v1/intents/buy",
+        json={"intent_id": intent_id, "trading_date": DAY.isoformat(), "symbol": symbol, "qty": 10},
+    )
+
+
+def test_healthz(ctx):
+    _, _, _, client = ctx
+    r = client.get("/v1/healthz")
+    assert r.status_code == 200 and r.json()["status"] == "ok"
+
+
+def test_buy_intent_admits_and_transitions(ctx):
+    repo, _, _, client = ctx
+    r = _buy(client, "buy-1")
+    assert r.status_code == 200
+    body = r.json()
+    assert body["status"] == "admitted" and body["slot_id"]
+    slot = repo.fetch_slot(__import__("uuid").UUID(body["slot_id"]))
+    assert slot.status is SlotState.PENDING_BUY and slot.symbol == "005930"
+
+
+def test_buy_intent_idempotent_resubmit(ctx):
+    repo, _, _, client = ctx
+    r1 = _buy(client, "buy-dup")
+    r2 = _buy(client, "buy-dup")  # same intent_id
+    assert r1.json() == r2.json()  # identical decision
+    # only ONE slot moved out of idle
+    pending = [s for s in repo.list_slots(DAY) if s.status is SlotState.PENDING_BUY]
+    assert len(pending) == 1
+
+
+def test_buy_intent_rejected_when_no_idle(ctx):
+    _, _, _, client = ctx
+    for i in range(3):
+        assert _buy(client, f"buy-fill-{i}").json()["status"] == "admitted"
+    r = _buy(client, "buy-overflow")
+    assert r.json()["status"] == "rejected" and r.json()["reason"] == "no_idle_slot"
+
+
+def test_sell_intent_requires_holding(ctx):
+    repo, _, _, client = ctx
+    # a freshly bought slot is pending_buy, not holding -> sell rejected
+    slot_id = _buy(client, "buy-for-sell").json()["slot_id"]
+    r = client.post("/v1/intents/sell", json={"intent_id": "sell-1", "slot_id": slot_id})
+    assert r.json()["status"] == "rejected" and r.json()["reason"].startswith("slot_not_holding")
+
+
+def test_sell_intent_admits_from_holding(ctx):
+    repo, svc, _, client = ctx
+    import uuid
+
+    slot_id = uuid.UUID(_buy(client, "buy-h").json()["slot_id"])
+    svc.transit_slot(slot_id, SlotState.PENDING_BUY, SlotState.HOLDING, reason="filled", actor="t")
+    r = client.post("/v1/intents/sell", json={"intent_id": "sell-h", "slot_id": str(slot_id)})
+    assert r.json()["status"] == "admitted"
+    assert repo.fetch_slot(slot_id).status is SlotState.PENDING_SELL
+
+
+def test_get_intent_roundtrip(ctx):
+    _, _, _, client = ctx
+    _buy(client, "buy-q")
+    r = client.get("/v1/intents/buy-q")
+    assert r.status_code == 200 and r.json()["status"] == "admitted"
+    assert client.get("/v1/intents/does-not-exist").status_code == 404
+
+
+def test_list_slots_and_capacity(ctx):
+    _, _, _, client = ctx
+    _buy(client, "buy-c")
+    slots = client.get(
+        "/v1/slots", params={"status": "pending_buy", "trading_date": DAY.isoformat()}
+    ).json()
+    assert len(slots) == 1 and slots[0]["status"] == "pending_buy"
+    cap = client.get(
+        "/v1/capacity", params={"total_slots": 3, "trading_date": DAY.isoformat()}
+    ).json()
+    assert cap["idle_count"] == 2 and cap["pending_count"] == 1 and cap["total_slots"] == 3