test(validations-ogParamsSchema): add comprehensive schema tests (JhaSourav07#3094)

## Description

Fixes JhaSourav07#2326 
## Title

test(validations-ogParamsSchema): add comprehensive schema tests


## Summary

Added a dedicated test suite for `ogParamsSchema` in
`lib/validations.ogParamsSchema.test.ts`.

The tests cover:

* successful parsing of valid OpenGraph parameters
* default theme handling
* username fallback behavior
* fallback to `"unknown"` when no user values are provided
* valid hex color parsing behavior
* invalid color handling for malformed hex values

## Changes Made

* Created `lib/validations.ogParamsSchema.test.ts`
* Added 6 focused Vitest test cases
* Verified schema transforms and fallback behavior using `safeParse`

## Validation

```bash
npx vitest lib/validations.ogParamsSchema.test.ts
npm run lint
npm run format
```

## Pillar

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

## Visual Preview

## 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

lib/validations.ogParamsSchema.test.ts

@@ -0,0 +1,92 @@
+import { describe, expect, it } from 'vitest';
+import { ogParamsSchema } from './validations';
+
+describe('ogParamsSchema', () => {
+  it('parses valid OpenGraph parameters successfully', () => {
+    const result = ogParamsSchema.safeParse({
+      user: 'octocat',
+      theme: 'dark',
+      bg: 'ffffff',
+      text: '000000',
+      accent: 'ff0000',
+    });
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.user).toBe('octocat');
+      expect(result.data.theme).toBe('dark');
+      expect(result.data.bg).toBe('ffffff');
+      expect(result.data.text).toBe('000000');
+      expect(result.data.accent).toBe('ff0000');
+    }
+  });
+
+  it('applies default theme when omitted', () => {
+    const result = ogParamsSchema.safeParse({
+      user: 'octocat',
+    });
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.theme).toBe('dark');
+    }
+  });
+
+  it('falls back to username when user is not provided', () => {
+    const result = ogParamsSchema.safeParse({
+      username: 'fallback-user',
+    });
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.user).toBe('fallback-user');
+    }
+  });
+
+  it('falls back to unknown when both user and username are missing', () => {
+    const result = ogParamsSchema.safeParse({});
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.user).toBe('unknown');
+    }
+  });
+
+  it('normalizes valid hex color values', () => {
+    const result = ogParamsSchema.safeParse({
+      user: 'octocat',
+      bg: 'ABCDEF',
+      text: '123456',
+      accent: 'ff00ff',
+    });
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.bg).toBe('ABCDEF');
+      expect(result.data.text).toBe('123456');
+      expect(result.data.accent).toBe('ff00ff');
+    }
+  });
+
+  it('falls back to default color for invalid hex values', () => {
+    const result = ogParamsSchema.safeParse({
+      user: 'octocat',
+      bg: 'invalid-color',
+      text: 'xyz',
+      accent: '12345',
+    });
+
+    expect(result.success).toBe(true);
+
+    if (result.success) {
+      expect(result.data.bg).toBeUndefined();
+      expect(result.data.text).toBeUndefined();
+      expect(result.data.accent).toBeUndefined();
+    }
+  });
+});