Adds automatic scope normalization to prevent URL encoding issues when
OIDC_SCOPE contains extra whitespace, tabs, or newlines. This addresses
issue #1056 where spaces in the scope value could cause authentication
failures in some environments.
Changes:
- Added normalizeScope() function to trim and collapse whitespace
- Automatically adds 'openid' scope if missing with warning
- Updated both single and multi-provider configurations
- Added comprehensive tests for scope normalization edge cases
- Added service tests to verify authorization URL construction
- Updated documentation with scope formatting guidance
Fixes#1056