feat: consolidate backend and docker-compose setup

backend/db/migrations/001_init_schema.sql

@@ -0,0 +1,29 @@
+-- Migration: 001_init_schema
+-- Description: Initialize schema for documents and ocr_items
+
+CREATE TABLE IF NOT EXISTS documents (
+    id SERIAL PRIMARY KEY,
+    filename VARCHAR(255) UNIQUE NOT NULL,
+    upload_time TIMESTAMP NOT NULL DEFAULT NOW(),
+    size INTEGER NOT NULL DEFAULT 0,
+    parsed BOOLEAN NOT NULL DEFAULT FALSE,
+    metadata JSONB,
+    layout_parsing_result JSONB,
+    is_sample BOOLEAN NOT NULL DEFAULT FALSE
+);
+
+CREATE TABLE IF NOT EXISTS ocr_items (
+    id SERIAL PRIMARY KEY,
+    document_id INTEGER NOT NULL REFERENCES documents(id) ON DELETE CASCADE,
+    row_index INTEGER NOT NULL,
+    kode_barang_original VARCHAR(255),
+    kode_barang VARCHAR(255),
+    nama_barang VARCHAR(255),
+    banyak_original VARCHAR(255),
+    banyak VARCHAR(255),
+    jumlah_original VARCHAR(255),
+    jumlah VARCHAR(255),
+    is_flagged BOOLEAN NOT NULL DEFAULT FALSE,
+    remark VARCHAR(1000),
+    UNIQUE(document_id, row_index)
+);