PKCE

[Ghostboo124]

Add PKCE support

Copilot Overview (i just wanted to see what it would do):

This pull request introduces Proof Key for Code Exchange (PKCE) support to the OAuth implementation, updates the documentation for both OAuth and OIDC guides with improved examples and formatting, and makes several minor improvements and corrections to the developer documentation. Additionally, it includes a database migration to support PKCE and updates the schema accordingly.

OAuth PKCE Support and Documentation:

• Added a database migration (enable_pkce.rb) and updated the schema to support code_challenge and code_challenge_method fields in the oauth_access_grants table, enabling PKCE for OAuth flows. [1] [2] [3]
• Expanded the OAuth guide (oauth-guide.md.erb) with a detailed section on using PKCE, including step-by-step instructions, example requests, and error handling.

OIDC and OAuth Documentation Improvements:

• Improved code examples and formatting in both OAuth and OIDC guides by wrapping API example URLs in scrollable containers for better readability and consistency. [1] [2] [3]
• Updated and corrected markdown tables for OIDC standard and custom scopes, and clarified scope restrictions in the documentation. [1] [2] [3]
• Standardized TypeScript code samples in the OIDC guide to use semicolons and improved code consistency. [1] [2] [3]

Minor Documentation and UI Corrections:

• Fixed minor markdown and typographical issues in both guides, such as italicization and code block formatting.
• Minor UI adjustment in the step-up authentication page, though the change appears incomplete and may need review.

Schema and Migration Updates:

• Updated db/schema.rb to reflect the new PKCE columns, added tables for analytics (ahoy_events, ahoy_visits), and included other schema changes to stay in sync with migrations. [1] [2] [3]

These changes collectively improve both the security and developer experience of the OAuth and OIDC integrations, especially for native and single-page applications.

[Ghostboo124]

This fixes Issue #167

[24c02]

i see a bunch of unrelated changes in here?

[Ghostboo124]

db/migrate/20260121045934_enable_pkce.rb, db/analytics_schema.rb, db/schema.rb are all from the doorkeeper PKCE migration that the doorkeeper docs told me to run.

app/views/step_up/new.html.erb was changed when I ran the lint script. (kind of unrelated, but the old README told me to run the lint script, I don't know about the new one)

app/views/docs/oidc-guide.md.erb was me fixing a bug where one of the requests went off the screen and a duplicated word (so, yes, unrelated)

app/views/docs/oauth-guide.md.erb was me adding a guide for PKCE