Update auto-generated opencode.json defaults to model IDs that are
valid as of April 2026:
- anthropic: claude-sonnet-4-5 -> claude-sonnet-4-6
- openai: gpt-4o (retired Apr 3 2026) -> gpt-5.4
- bedrock: anthropic.claude-sonnet-4-5-v1 (invalid) ->
global.anthropic.claude-sonnet-4-5-20250929-v1:0
The Bedrock ID now uses the global inference profile (no regional
10% premium) and includes the required date stamp and :0 suffix.
Integrate oh-my-opencode-slim as an opt-in feature via INSTALL_OMOS build arg.
A single build arg installs Bun, tmux, and the plugin; runtime activation is
controlled by ENABLE_OMOS and related env vars in the entrypoint.
joakimp