test: add Vitest and Phase 1 pure-helper suite

Introduce automated testing to a project that had no test runner, no
test script and no CI. Vitest fits the existing Vite setup with near-zero
config; a standalone vitest.config.ts wires the @/ alias via
vite-tsconfig-paths and runs in the node environment, avoiding the app's
Tailwind/React/WASM plugins that pure-logic tests do not need.

Cover the cheapest, highest-value surface first: pure helpers with no DOM,
WASM or database. getNextSequence and cloneField (field.ts), the
charset/collation and SQLite integer-column reordering plus enum naming
(render-uttils.ts), and orderTables including the CircularDependencyError
cycle path that backs the Foreign Key Cycle Detection feature.

The build's tsc step is unaffected (plain tsc no-ops on the root config)
and the new files typecheck clean under strict and lint clean.

src/utils/render/render-uttils.test.ts

@@ -0,0 +1,68 @@
+import { describe, it, expect } from "vitest";
+
+import {
+  fixCharsetPlacement,
+  fixSQLiteColumnOrder,
+  getPostgresEnumName,
+} from "./render-uttils";
+
+import { FieldType } from "@/lib/schemas/field-schema";
+import { TableType } from "@/lib/schemas/table-schema";
+
+describe("fixCharsetPlacement", () => {
+  it("moves CHARACTER SET / COLLATE directly after the column type", () => {
+    const sql = [
+      "CREATE TABLE users (",
+      "name VARCHAR(255) NOT NULL CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,",
+      "email TEXT",
+      ")",
+    ].join("\n");
+
+    const out = fixCharsetPlacement(sql);
+
+    expect(out).toContain(
+      "name VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL",
+    );
+    // charset/collation must sit before the remaining attributes
+    const line = out.split("\n").find((l) => l.includes("CHARACTER SET")) ?? "";
+
+    expect(line.indexOf("CHARACTER SET")).toBeLessThan(
+      line.indexOf("NOT NULL"),
+    );
+  });
+
+  it("leaves columns without charset/collation untouched", () => {
+    const sql = ["CREATE TABLE t (", "email TEXT", ")"].join("\n");
+
+    expect(fixCharsetPlacement(sql)).toContain("email TEXT");
+  });
+});
+
+describe("fixSQLiteColumnOrder", () => {
+  it("reorders INTEGER PK attributes to PRIMARY KEY / AUTOINCREMENT / NOT NULL", () => {
+    const sql = [
+      "CREATE TABLE t (",
+      "id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT",
+      ")",
+    ].join("\n");
+
+    expect(fixSQLiteColumnOrder(sql)).toContain(
+      "id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL",
+    );
+  });
+
+  it("leaves non-primary-key INTEGER columns unchanged", () => {
+    const sql = ["CREATE TABLE t (", "age INTEGER DEFAULT 0", ")"].join("\n");
+
+    expect(fixSQLiteColumnOrder(sql)).toContain("age INTEGER DEFAULT 0");
+  });
+});
+
+describe("getPostgresEnumName", () => {
+  it("builds <table>_<lowercased field>_enum", () => {
+    const table = { name: "Order" } as TableType;
+    const field = { name: "Status" } as FieldType;
+
+    expect(getPostgresEnumName(table, field)).toBe("Order_status_enum");
+  });
+});