fix(opencode): use ACP-reported reasoning effort options (#853)

* fix(opencode): use ACP-reported reasoning effort options

Expose thought_level options from OpenCode ACP to the web UI via RPC/API
instead of hardcoded presets, and validate effort values before setConfigOption.

Fixes #852

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(opencode): sync hub effort after coerced setConfigOption

When resolveThoughtLevelEffort falls back to a different supported value,
roll back session state after a successful ACP update so keepalive and the
web UI do not keep advertising the rejected effort.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/api/client.ts

@@ -33,6 +33,7 @@ import type {
     MachineListDirectoryResponse,
     MachinePathsExistsResponse,
     OpencodeModelsResponse,
+    OpencodeReasoningEffortResponse,
     ReopenSessionResponse,
     UploadFileResponse
 } from '@hapi/protocol/apiTypes'
@@ -564,6 +565,12 @@ export class ApiClient {
         )
     }
 
+    async getSessionOpencodeReasoningEffortOptions(sessionId: string): Promise<OpencodeReasoningEffortResponse> {
+        return await this.request<OpencodeReasoningEffortResponse>(
+            `/api/sessions/${encodeURIComponent(sessionId)}/opencode-reasoning-effort-options`
+        )
+    }
+
     async getSessionCursorModels(sessionId: string): Promise<CursorModelsResponse> {
         return await this.request<CursorModelsResponse>(
             `/api/sessions/${encodeURIComponent(sessionId)}/cursor-models`