feat(pprof): add support for configurable pprof HTTP debug server

Merge branch 'dev' into codex

refactor(codex): remove codex instructions injection support

feat(config): track routing and cloak changes in config diff

refactor(api): centralize config change logging

fix(config): add codex instructions enabled change to config change details

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

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

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

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