test(validations): add comprehensive org parameter validation tests

[sodium16]

Description

Fixes #1429

Pillar

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

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[Aamod007]

This PR replaces (deletes) the existing returns 400 when the user parameter is missing test which verified the error response structure (body.error, body.details). The remaining does not hit the GitHub API when user is missing only checks that fetch isn't called — it doesn't assert the response body format.

Please keep the missing user test and add the org validation test alongside it instead of replacing it.

[JhaSourav07]

@sodium16

please see the mentor comment and fix it so that i can merge your PR