Add OAuth providers migration

[premtsd-code]

Summary

• Adds TYPE_OAUTH_PROVIDERS to GROUP_AUTH_RESOURCES for migrating the project's OAuth2 provider configuration map.
• Source (Sources/Appwrite) reads $project->oAuthProviders and emits one OAuthProviders singleton carrying key/enabled/appId for each provider.
• Destination (Destinations/Appwrite) merges the entries into the project doc's oAuthProviders map as flat {key}Enabled / {key}Appid keys via dbForPlatform (mirrors the destination path used by auth-methods / policies).
• {key}Secret is intentionally not migrated — the source API never exposes secrets and the destination user must re-enter them post-migration. Same caveat as the SMTP password handling.
• Grouped under GROUP_AUTH (not GROUP_INTEGRATIONS) — OAuth providers are auth methods that happen to use external identity providers; same group as TYPE_AUTH_METHODS and TYPE_POLICIES.

Test plan

• CI lints + tests green
• E2E testAppwriteMigrationOAuthProviders (in appwrite/appwrite) passes

[greptile-apps]

Greptile Summary

This PR introduces OAuth2 provider configuration migration between Appwrite projects. It adds a new OAuth2Provider resource class with a curated allow-list of safe-to-migrate fields per provider, source-side extraction via listOAuth2Providers, and destination-side direct DB writes that merge non-secret config (endpoints, prompts, tenant IDs) into the {key}Secret JSON blob while intentionally omitting client secrets.

• OAuth2Provider uses a two-target field model (appId / secret) with per-provider rename mappings; client secrets and Apple's p8 file are never in scope, providing a clean security boundary.
• mergeJsonSecret correctly guards the empty-fields case (returns existing string unchanged) and handles malformed JSON gracefully; the isConfigured filter on the source side ensures unconfigured providers are never emitted.
• The destination applies one read-modify-write DB cycle per provider rather than batching all providers into a single update, which multiplies DB round trips for projects with many configured providers.

Confidence Score: 5/5

The change is safe to merge; it adds a self-contained new migration path with no modifications to existing resource types or write paths.

The core logic — allow-list field mapping, conditional secret merging, and isConfigured filtering — is correct and consistent with how auth methods and policies are handled in the same codebase. The null guard on listOAuth2Providers().providers is present, and mergeJsonSecret correctly short-circuits on empty fields.

No files require special attention; the implementation is straightforward and mirrors established patterns in the codebase.

Important Files Changed

Filename	Overview
src/Migration/Resources/Auth/OAuth2/OAuth2Provider.php	New resource class with a well-structured provider allow-list and safe field mapping; minor missing null-coalescing on $array['id'] in fromArray
src/Migration/Destinations/Appwrite.php	Adds createOAuth2Provider and mergeJsonSecret using the established read-modify-write pattern; mergeJsonSecret is robust, but the per-provider DB read+write loop is N-fold instead of a single batch operation
src/Migration/Sources/Appwrite.php	Adds exportOAuth2Providers / getOAuth2ProviderResources with correct null-guard on providers and proper isConfigured filtering; calculateResourcesReport count matches what's actually exported
src/Migration/Resource.php	Adds TYPE_OAUTH2_PROVIDER constant with clear rationale (shared type avoids statusCounters column overflow); inserted into ALL_RESOURCES correctly
src/Migration/Transfer.php	Adds TYPE_OAUTH2_PROVIDER to GROUP_AUTH_RESOURCES and the public resources array; no logic changes
tests/Migration/Unit/Adapters/MockDestination.php	Registers TYPE_OAUTH2_PROVIDER in the mock destination's supported types list
tests/Migration/Unit/Adapters/MockSource.php	Registers TYPE_OAUTH2_PROVIDER in the mock source's supported types list

_{Reviews (24): Last reviewed commit: "Remove OAuth provider unit tests" | Re-trigger Greptile}

[abnegate]

Can we generalize and have 1 class for all? Much easier to maintain