opencode: remove oh-my-openagent from all profiles

Drops the plugin entry and the agent/* model aliases, sets plain default
models, and removes the OMO roster swap from opencode.zsh.

common/claude/CLAUDE.md

@@ -3,7 +3,7 @@
 ## LLM / inference stack
 
 Connor runs a self-hosted inference stack: LiteLLM proxy in front of a local GPU
-model (llama-swap), OpenAI, Anthropic, and Moonshot/Kimi, with OpenCode + OMO on
+model (llama-swap), OpenAI, Anthropic, and Moonshot/Kimi, with OpenCode on
 top. **Before touching anything under `~/config/litellm/`, `~/.config/opencode/`,
 or the model routing, read `~/guides/llm/robots.md`.** It carries the design
 decisions, the measured data, and — more importantly — the specific wrong
@@ -79,13 +79,11 @@ The five things most likely to waste an hour if you don't know them:
    VRAM buys prefill, not decode. Don't recommend a bigger GPU without checking
    which wall you're actually against.
 
-9. **The OMO agent aliases embed their model family on purpose** —
-   `personal/atlas-kimi-k2.7-code`, not `personal/atlas`. OMO picks its
-   per-model prompt by string-matching the *last path segment* of the model
-   name, so a "tidy-up" rename silently disables every Kimi/GPT-specific prompt
-   and guard with no error. **Never shorten them.** `local/librarian` and
-   `local/explore` are deliberately left un-suffixed — `isGptModel` matches a
-   bare `"gpt"` substring and `gpt-oss-20b` would trip it.
+9. **OMO (oh-my-openagent) was removed from every OpenCode profile on
+   2026-10-29.** It injected its own skills and prompts into non-OMO agents
+   and used a lot of context. The `agent/*` and `personal/atlas-*` style
+   aliases in LiteLLM were for OMO's roster and are unused by OpenCode now;
+   OMO rewrote them at request time, so they 400 if called directly.
 
 Cost work: read `model_group`, never `model`, to attribute a request. Cost is
 driven by cache-read volume and context size far more than by model choice.