fix(github): skip assertPermissions when use_github_token is true

GitHub App bot actors (e.g. my-bot[bot]) return permission: none from
the collaborators API because Apps authenticate via installation tokens,
not as traditional collaborators.

When use_github_token is true, the caller is providing their own
GITHUB_TOKEN and managing authentication directly, making the
collaborator-level permission check both unnecessary and broken for
bot actors.

Closes #17224

packages/opencode/src/cli/cmd/github.ts

@@ -540,7 +540,12 @@ export const GithubRunCommand = cmd({
         }
         // Skip permission check and reactions for repo events (no actor to check, no issue to react to)
         if (isUserEvent) {
-          await assertPermissions()
+          // Skip permission check when using a custom GitHub token, since the caller
+          // manages their own auth and the collaborator API returns "none" for GitHub
+          // App bot actors (e.g. my-bot[bot]) even though they have valid installation tokens.
+          if (!useGithubToken) {
+            await assertPermissions()
+          }
           await addReaction(commentType)
         }