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>

trex_core/adapters/persistence/sql/001_create_slot_core_tables.sql

@@ -0,0 +1,74 @@
+-- BAT-002 / REQ-006: trex-core-owned slot-core schema.
+--
+-- Authored fresh for trex-core, keyed to the Slot column contract in
+-- dcy-001 Appendix A (orbit-v2 DDL used only as reference). Scope: slice 1.
+-- Excludes daily_slot_archive / retention prune (out of scope, dcy-002).
+
+-- daily_slot — current lifecycle state (single-writer source of truth).
+-- Columns mirror dcy-001 Appendix A (16 columns) and trex_core EXPECTED_SLOT_FIELDS.
+CREATE TABLE IF NOT EXISTS daily_slot (
+    slot_id             UUID PRIMARY KEY,
+    trading_date        DATE NOT NULL,
+    status              TEXT NOT NULL CHECK (
+        status IN ('idle','pending_buy','holding','pending_sell','closed','error')
+    ),
+    symbol              TEXT,
+    qty                 NUMERIC(18, 4),
+    avg_price           NUMERIC(18, 4),
+    entry_price         NUMERIC(18, 4),
+    allocated_capital   NUMERIC(18, 2),
+    order_id            TEXT,
+    strategy_id         TEXT,
+    broker_order_id     TEXT,
+    portfolio_id        TEXT,
+    sell_strategy_id    TEXT,
+    forced_close_at     TIMESTAMPTZ,
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC'),
+    updated_at          TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC')
+);
+
+CREATE INDEX IF NOT EXISTS idx_daily_slot_trading_date_status
+    ON daily_slot (trading_date, status);
+
+-- daily_symbol_entries — per-day re-entry counter (decision input).
+CREATE TABLE IF NOT EXISTS daily_symbol_entries (
+    trading_date    DATE        NOT NULL,
+    symbol          TEXT        NOT NULL,
+    entry_count     INTEGER     NOT NULL DEFAULT 0,
+    last_entry_at   TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC'),
+    PRIMARY KEY (trading_date, symbol)
+);
+
+-- slot_transition_log — append-only audit of every transition.
+CREATE TABLE IF NOT EXISTS slot_transition_log (
+    log_id          BIGSERIAL PRIMARY KEY,
+    slot_id         UUID NOT NULL,
+    from_state      TEXT NOT NULL,
+    to_state        TEXT NOT NULL,
+    ts              TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC'),
+    reason          TEXT NOT NULL,
+    actor           TEXT NOT NULL,
+    extra           JSONB NOT NULL DEFAULT '{}'::jsonb
+);
+
+CREATE INDEX IF NOT EXISTS idx_slot_transition_log_slot_id_ts
+    ON slot_transition_log (slot_id, ts);
+
+-- intent_log — durable idempotency store + audit for accepted intents
+-- (dcy-002 OQ-1). intent_id UNIQUE is the dedup gate that prevents double
+-- slot transitions on at-least-once retransmission. Precursor to a full
+-- outbox (status column reserved); async consumer loop deferred to the
+-- broker-execution Discovery.
+CREATE TABLE IF NOT EXISTS intent_log (
+    intent_id     TEXT PRIMARY KEY,
+    intent_type   TEXT NOT NULL CHECK (intent_type IN ('buy','sell')),
+    payload       JSONB NOT NULL DEFAULT '{}'::jsonb,
+    status        TEXT NOT NULL DEFAULT 'processing'
+        CHECK (status IN ('processing','admitted','rejected')),
+    slot_id       UUID,
+    reason        TEXT,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC'),
+    updated_at    TIMESTAMPTZ NOT NULL DEFAULT (now() AT TIME ZONE 'UTC')
+);
+
+CREATE INDEX IF NOT EXISTS idx_intent_log_status ON intent_log (status);