feat(hashline-edit): add anchor insert modes and strict insert validation

bun-test.d.ts

@@ -0,0 +1,23 @@
+declare module "bun:test" {
+  export function describe(name: string, fn: () => void): void
+  export function it(name: string, fn: () => void | Promise<void>): void
+  export function beforeEach(fn: () => void | Promise<void>): void
+  export function afterEach(fn: () => void | Promise<void>): void
+  export function beforeAll(fn: () => void | Promise<void>): void
+  export function afterAll(fn: () => void | Promise<void>): void
+  export function mock<T extends (...args: never[]) => unknown>(fn: T): T
+
+  interface Matchers {
+    toBe(expected: unknown): void
+    toEqual(expected: unknown): void
+    toContain(expected: unknown): void
+    toMatch(expected: RegExp | string): void
+    toHaveLength(expected: number): void
+    toBeGreaterThan(expected: number): void
+    toThrow(expected?: RegExp | string): void
+    toStartWith(expected: string): void
+    not: Matchers
+  }
+
+  export function expect(received: unknown): Matchers
+}