Make proxy authentication bearer-only across every client (#1096)

Establish single-owner runtime with stream-safe provider hot swaps (#1036)

Restore protocol-correct provider errors without client retry loops (#1033)

Move runtime packages under src namespace (#1029)

fix: normalize proxy auth token whitespace

Allow unauthenticated root probes

Major refactor: API, providers, messaging, and Anthropic protocol

Fixes for issue 113 and 116

Implement optional authentication (Anthropic style) (#80)