fix(variant): respect TUI variant and enforce max in ultrawork mode

- keyword-detector: always set variant to 'max' when ultrawork/ulw keyword detected
- chat-message: remove variant resolution logic to passthrough TUI variant unchanged
- Tests updated to reflect new behavior

🤖 Generated with OhMyOpenCode assistance

src/plugin/chat-message.ts

@@ -1,15 +1,8 @@
 import type { OhMyOpenCodeConfig } from "../config"
 import type { PluginContext } from "./types"
 
-import {
-  applyAgentVariant,
-  resolveAgentVariant,
-  resolveVariantForModel,
-} from "../shared/agent-variant"
 import { hasConnectedProvidersCache } from "../shared"
-import {
-  setSessionAgent,
-} from "../features/claude-code-session-state"
+import { setSessionAgent } from "../features/claude-code-session-state"
 import { applyUltraworkModelOverrideOnMessage } from "./ultrawork-model-override"
 
 import type { CreatedHooks } from "../create-hooks"
@@ -57,25 +50,7 @@ export function createChatMessageHandler(args: {
     const message = output.message
 
     if (firstMessageVariantGate.shouldOverride(input.sessionID)) {
-      if (message["variant"] === undefined) {
-        const variant =
-          input.model && input.agent
-            ? resolveVariantForModel(pluginConfig, input.agent, input.model)
-            : resolveAgentVariant(pluginConfig, input.agent)
-        if (variant !== undefined) {
-          message["variant"] = variant
-        }
-      }
       firstMessageVariantGate.markApplied(input.sessionID)
-    } else {
-      if (input.model && input.agent && message["variant"] === undefined) {
-        const variant = resolveVariantForModel(pluginConfig, input.agent, input.model)
-        if (variant !== undefined) {
-          message["variant"] = variant
-        }
-      } else {
-        applyAgentVariant(pluginConfig, input.agent, message)
-      }
     }
 
     await hooks.stopContinuationGuard?.["chat.message"]?.(input)