refactor(config): rename oauth-model-mappings to oauth-model-alias

refactor(config): replace `nonstream-keepalive` with `nonstream-keepalive-interval`

feat(api): add non-streaming keep-alive support for idle timeout prevention

feat(config): add support for `Fork` in OAuth model mappings with alias handling

refactor(watcher): extract model summary functions to dedicated file

feat(watcher): add Gemini models and OAuth model mappings change detection

feat(amp): add per-client upstream API key mapping support

feat(cliproxy): implement model aliasing and hashing for Codex configurations, enhance request routing logic, and normalize Codex model entries

fix(config): use correct formatting function for prefix change details

test(config): add unit tests for model prefix changes in config diff

feat(diff): add support for model prefix changes in config diff logic

Merge branch 'dev' into watcher

refactor(diff): improve security and stability of config change detection

refactor(watcher): extract config diff helpers