fix: add downloads array to plugin.json (required by wfctl external plugin validation)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: intel352

plugin.json

@@ -10,6 +10,33 @@
     "keywords": ["github", "webhook", "git", "actions", "ci", "cd", "integration", "pull-request", "release"],
     "homepage": "https://github.com/GoCodeAlone/workflow-plugin-github",
     "repository": "https://github.com/GoCodeAlone/workflow-plugin-github",
+    "downloads": [
+        {
+            "os": "linux",
+            "arch": "amd64",
+            "url": "https://github.com/GoCodeAlone/workflow-plugin-github/releases/download/v1.0.1/workflow-plugin-github-linux-amd64.tar.gz"
+        },
+        {
+            "os": "linux",
+            "arch": "arm64",
+            "url": "https://github.com/GoCodeAlone/workflow-plugin-github/releases/download/v1.0.1/workflow-plugin-github-linux-arm64.tar.gz"
+        },
+        {
+            "os": "darwin",
+            "arch": "amd64",
+            "url": "https://github.com/GoCodeAlone/workflow-plugin-github/releases/download/v1.0.1/workflow-plugin-github-darwin-amd64.tar.gz"
+        },
+        {
+            "os": "darwin",
+            "arch": "arm64",
+            "url": "https://github.com/GoCodeAlone/workflow-plugin-github/releases/download/v1.0.1/workflow-plugin-github-darwin-arm64.tar.gz"
+        },
+        {
+            "os": "windows",
+            "arch": "amd64",
+            "url": "https://github.com/GoCodeAlone/workflow-plugin-github/releases/download/v1.0.1/workflow-plugin-github-windows-amd64.tar.gz"
+        }
+    ],
     "moduleTypes": ["git.webhook", "github.app", "github.runner_provider"],
     "stepTypes": [
         "step.gh_action_trigger",