feat(sdk): app token organization switching

[markwylde]

Summary

• Add bearer access-token support to API organization listing and organization switch endpoint.
• Remove SDK "silent" organization-switch mode in favor of token-based switching.
• Update SDK docs and org-switching specs for the new flow.

Changes

• packages/api/src/controllers/user/organizations.ts: allow Authorization: Bearer app access token with fallback to session cookie.
• packages/api/src/controllers/user/token.ts: require access token in app-token switch and avoid setting first-party cookies.
• packages/api/src/controllers/user/oauthEndpoints.test.ts: cover token-based org switch and organization-list behaviors.
• packages/darkauth-client/src/index.ts + packages/darkauth-client/tests/organizations.test.js: remove silent mode and add access-token header flow for list/switch.
• packages/darkauth-client/README.md, specs/ORG_SWITCHING.md: document new integration contract and constraints.
• packages/api/src/http/routers/userRouter.ts, packages/api/src/controllers/user/authorize.ts: tiny style/formatting adjustments.

Commit list

• 98019a0 fix(api): require app access token for org switch APIs
• eefe700 feat(sdk): switch organization via access-token flow
• 4c51433 docs(organization): document app token organization switching path