Adds OpenCode (https://github.com/opencode-ai/opencode) as a supported
provider. OpenCode is an open-source terminal AI coding assistant with
an OpenAI-compatible API running locally.
Changes:
- open-sse/config/providers.js: add opencode baseUrl (localhost:4096)
with openai format (fully compatible, no custom headers needed)
- open-sse/services/model.js: add 'oc' alias → opencode
- src/shared/constants/providers.js: add opencode to subscription
providers with alias 'oc', icon 'terminal', color #E87040
Usage after setup: use model prefix 'oc/<model>' to route through
a running OpenCode instance (e.g. oc/claude-sonnet-4-5).
Closes#378
fcc8320753