Providers: add Opencode Go support (#42313)

* feat(providers): add opencode-go provider support and onboarding

* Onboard: unify OpenCode auth handling openclaw#42313 thanks @ImLukeF

* Docs: merge OpenCode Zen and Go docs openclaw#42313 thanks @ImLukeF

* Update CHANGELOG.md

---------

Co-authored-by: Ubuntu <ubuntu@vps-90352893.vps.ovh.ca>
Co-authored-by: Vincent Koc <vincentkoc@ieee.org>

docs/docs.json

@@ -103,6 +103,10 @@
       "source": "/opencode",
       "destination": "/providers/opencode"
     },
+    {
+      "source": "/opencode-go",
+      "destination": "/providers/opencode-go"
+    },
     {
       "source": "/qianfan",
       "destination": "/providers/qianfan"
@@ -1013,8 +1017,7 @@
                   "tools/browser",
                   "tools/browser-login",
                   "tools/chrome-extension",
-                  "tools/browser-linux-troubleshooting",
-                  "tools/browser-wsl2-windows-remote-cdp-troubleshooting"
+                  "tools/browser-linux-troubleshooting"
                 ]
               },
               {
@@ -1112,6 +1115,7 @@
                   "providers/nvidia",
                   "providers/ollama",
                   "providers/openai",
+                  "providers/opencode-go",
                   "providers/opencode",
                   "providers/openrouter",
                   "providers/qianfan",