[Bug](greenhouse): organization name incorrectly extracted when app mounted with basePath

[ArtieReus]

Description

When the greenhouse app is mounted with a static basePath (e.g., /greenhouse), the organization extraction logic incorrectly extracts the
basePath as the organization name instead of the actual organization.

Steps to Reproduce

1. Mount the greenhouse app with a basePath: /greenhouse
2. Navigate to /greenhouse/demo
3. Observe that the app extracts "greenhouse" as the organization name
4. Expected: Should extract "demo" as the organization name

Current Behavior

URL: /greenhouse/demo
Extracted org: "greenhouse" ❌

The extractOrganizationName function in AuthProvider.tsx takes the first path segment without considering the static basePath that the
app is mounted at.

Expected Behavior

URL: /greenhouse/demo
Expected org: "demo" ✅

The function should strip the static basePath (/greenhouse) before extracting the organization name from the remaining path.

• OS: [e.g., Windows, macOS, Linux]
• Browser: [e.g., Chrome, Firefox, Safari]
• Version: [e.g., 22]

Additional Context

[ArtieReus]

Fixed with: https://github.wdf.sap.corp/sap-cloud-infrastructure/greenhouse-deployment/pull/109