feat(BE): finance (payment, initial_balance, injection). fix(BE): kandang capacity

internal/database/migrations/20251224033033_create_payment_table.up.sql

@@ -0,0 +1,22 @@
+CREATE TABLE IF NOT EXISTS payments (
+    id BIGSERIAL PRIMARY KEY,
+    payment_code VARCHAR(50) NOT NULL,
+    reference_number VARCHAR(100) NULL,
+    transaction_type VARCHAR(50),
+    party_type VARCHAR(50) NOT NULL,
+    party_id BIGINT NOT NULL,
+    payment_date TIMESTAMPTZ NOT NULL,
+    payment_method VARCHAR(20) NOT NULL,
+    bank_id BIGINT NULL REFERENCES banks(id) ON DELETE RESTRICT ON UPDATE CASCADE,
+    direction VARCHAR(5) NOT NULL,
+    nominal NUMERIC(15, 3) NOT NULL,
+    notes TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at TIMESTAMPTZ NULL,
+    created_by BIGINT REFERENCES users (id) ON DELETE SET NULL ON UPDATE CASCADE
+);
+
+-- Indexes
+CREATE INDEX payments_party_polymorphic ON payments (party_type, party_id);
+CREATE INDEX idx_payments_bank_id ON payments (bank_id);