Fix external plugin gate manifest paths and diagnostics (#2261)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

.github/workflows/external-plugin-pr-quality-gates.yml

@@ -200,6 +200,18 @@ jobs:
               : qualityResult.overall_status === 'pass' || !shouldRun
                 ? '## ✅ External plugin PR checks passed'
                 : '## ⚠️ External plugin PR checks need maintainer follow-up';
+            const formatGateOutput = (pluginName, gateName, gateStatus, rawOutput) => {
+              const output = String(rawOutput || '').trim() || '_No output captured._';
+              return [
+                '<details>',
+                `<summary>${pluginName} — ${gateName} (${gateStatus || 'not_run'})</summary>`,
+                '',
+                '```text',
+                output,
+                '```',
+                '</details>',
+              ].join('\n');
+            };
 
             const rows = checkedPlugins.length > 0
               ? checkedPlugins.map((entry) => {
@@ -211,6 +223,21 @@ jobs:
                   return `| ${name} | ${quality.vally_lint_status || 'not_run'} | ${quality.smoke_status || 'not_run'} | ${quality.overall_status || 'not_run'} | ${sourceCell} |`;
                 })
               : ['| _none_ | not_run | not_run | not_run | _n/a_ |'];
+            const failureDetails = checkedPlugins.flatMap((entry) => {
+              const name = String(entry?.name || 'unknown');
+              const quality = entry?.quality || {};
+              const shouldShowVally = quality.vally_lint_status === 'fail' || quality.vally_lint_status === 'infra_error' || String(quality.vally_lint_output || '').trim().length > 0;
+              const shouldShowSmoke = quality.smoke_status === 'fail' || quality.smoke_status === 'infra_error' || String(quality.smoke_output || '').trim().length > 0;
+
+              const details = [];
+              if (shouldShowVally) {
+                details.push(formatGateOutput(name, 'vally lint', quality.vally_lint_status, quality.vally_lint_output));
+              }
+              if (shouldShowSmoke) {
+                details.push(formatGateOutput(name, 'install smoke test', quality.smoke_status, quality.smoke_output));
+              }
+              return details;
+            });
 
             const body = [
               marker,
@@ -225,6 +252,14 @@ jobs:
               '|---|---|---|---|---|',
               ...rows,
               '',
+              ...(failureDetails.length > 0
+                ? [
+                    '### Gate output details',
+                    '',
+                    ...failureDetails,
+                    '',
+                  ]
+                : []),
               String(qualityResult.summary || '').trim() || '_No summary provided._',
             ].join('\n');
 

eng/external-plugin-quality-gates.mjs

@@ -140,7 +140,7 @@ function cloneSubmissionRepository(workDir, plugin) {
 // NOTE: Keep in sync with EXTERNAL_PLUGIN_ROOT_MANIFEST_PATHS in external-plugin-validation.mjs
 const PLUGIN_JSON_CANDIDATES = [
   [".github", "plugin", "plugin.json"],
-  [".plugins", "plugin.json"],
+  [".plugin", "plugin.json"],
   ["plugin.json"],
 ];
 

eng/external-plugin-validation.mjs

@@ -27,7 +27,7 @@ export const EXTERNAL_PLUGIN_POLICIES = Object.freeze({
 const EXTERNAL_PLUGIN_ROOT_MANIFEST_PATHS = Object.freeze([
   "plugin.json",
   ".github/plugin/plugin.json",
-  ".plugins/plugin.json",
+  ".plugin/plugin.json",
 ]);
 
 function resolvePolicy(policy) {