Phase 23: warehouse-service Postgres persistence (bonded_* tables)

[munisp]

Phase 23 fix C2 — warehouse-service Postgres persistence

servces/go/warehouse-service/cmd/main.go kept bonded warehouses, duty-suspension bonds, and inventory in a process-local map (var store); all data was lost on restart while server/routers/warehouse.ts calls it live.

Change

• pgx v5 (v5.9.2) with pgxpool; DATABASE_URL env required. Fail-closed: the service log.Fatals on missing/unreachable DB at startup and never falls back to memory. The in-memory Store is deleted.
• Persists to the existing Drizzle-managed tables (bonded_warehouses, bonded_inventory, ex_bond_permits) — no new migration, drizzle/ untouched.
• All routes and JSON response shapes unchanged: GET /health, /api/warehouse/stats, /api/warehouse/list, /api/warehouse/inventory, POST /api/warehouse/register, /deposit, /release.
• ID semantics: serial ids are returned as strings; handlers accept numeric ids or license_no. Register is idempotent on license_no via ON CONFLICT (license_no) DO NOTHING.
• deposit: inserts bonded_inventory row + increments used_cbm in one transaction. The 1:1 duty-suspension bond is carried by the inventory row (duty_liability_usd); bond id == inventory id.
• release: sets status='ex_bonded'/released_at + decrements used_cbm (GREATEST(...,0)) + inserts an ex_bond_permits row (permit_no, duty_paid_usd, payment_ref, status 'used') — all in one transaction, mirroring the previous handler's bond-discharge logic.
• /health runs a real SELECT 1 (db:"ok", 503 when unreachable) and reports live table counts.

Verification

• go build ./..., go vet ./..., go test ./... all pass (Go 1.25.4).
• Also fixed a pre-existing test compile error (cmd/main_test.go: unused variable).

Notes / residual risk

• Table columns are integer cbm/kg/USD; float inputs are rounded (documented in code).
• Deployment must set DATABASE_URL for warehouse-service (service refuses to start without it — intended fail-closed).