merge: test(CustomizeCTA): add TypeScript compiler validation test suite (#8082)

## Description

This PR introduces a dedicated TypeScript compiler validation test suite
for the CustomizeCTA component to ensure its public type contract
remains stable and protected against future regressions.

## Changes Made
Added app/components/CustomizeCTA.type-compiler.test.tsx.
Verified that CustomizeCTA exports a valid function component.
Added compile-time validation for the component's ReactElement return
type.
Confirmed the component has no required parameters.
Ensured the component can be invoked without props.
Added a function signature stability check using expectTypeOf. 

Fixes #6827 

## Pillar

- [ ] 🎨 Pillar 1 — New Theme Design
- [x] 📐 Pillar 2 — Geometric SVG Improvement
- [x] 🕐 Pillar 3 — Timezone Logic Optimization
- [x] 🛠️ Other (Bug fix, refactoring, docs)

## Checklist before requesting a review:

- [x] I have read the `CONTRIBUTING.md` file.
- [x] I have tested these changes locally
(`localhost:3000/api/streak?user=YOUR_USERNAME`).
- [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors (CI will fail otherwise).
- [x] My commits follow the Conventional Commits format (e.g.,
`feat(themes): ...`, `fix(calculate): ...`).
- [x] I have updated `README.md` if I added a new theme or URL
parameter.
- [x] I have started the repo.
- [x] I have made sure that i have only one commit to merge in this PR.
- [x] The SVG output matches the CommitPulse "premium quality" aesthetic
standard (no raw elements, smooth animations, correct fonts).
- [x] (Recommended) I joined the CommitPulse Discord community for
contributor discussions, mentorship, and faster PR support.

Author: JhaSourav07

app/components/CustomizeCTA.type-compiler.test.tsx

@@ -0,0 +1,28 @@
+// app/components/CustomizeCTA.type-compiler.test.tsx
+
+import { describe, expect, it, expectTypeOf } from 'vitest';
+import type { ReactElement } from 'react';
+import { CustomizeCTA } from './CustomizeCTA';
+
+describe('CustomizeCTA TypeScript Compiler Validation', () => {
+  it('exports a function component', () => {
+    expect(typeof CustomizeCTA).toBe('function');
+    expectTypeOf(CustomizeCTA).toBeFunction();
+  });
+
+  it('returns a ReactElement', () => {
+    expectTypeOf<ReturnType<typeof CustomizeCTA>>().toMatchTypeOf<ReactElement>();
+  });
+
+  it('has no required parameters', () => {
+    expect(CustomizeCTA.length).toBe(0);
+  });
+
+  it('is callable without props', () => {
+    expect(() => CustomizeCTA()).not.toThrow();
+  });
+
+  it('maintains a stable function signature', () => {
+    expectTypeOf<typeof CustomizeCTA>().returns.toMatchTypeOf<ReactElement>();
+  });
+});