Bitbucket app passwords removal: what breaks

Bitbucket has removed app passwords, causing REST API 401 and git-over-HTTPS 410 errors. Users must transition to API tokens for humans and repository access tokens for CI to avoid failures. Different usernames identify credential types: account email for REST, x-bitbucket-api-token-auth for API tokens, and x-token-auth for access tokens. Stale keychain entries may override new tokens. On macOS, system gitconfig in Xcode can prevent global unset commands from removing old credential helpers.