feat: add GitHub repository dashboard with Prometheus metrics

ghtracker authenticates as a GitHub App and scans a configured list of repositories on a schedule. It serves a dashboard, a JSON state endpoint, a health probe and Prometheus metrics.

The dashboard lists only items that need attention: failing workflows, pull requests that wait too long or fail their checks, stale issues and projects that failed to scan. It has search, dynamic filters and a button that rescans on demand. The Vue app is embedded in the Go binary.

The client protects the GitHub rate limit with conditional requests, a request reserve and Retry-After handling.

eslint.config.js

@@ -0,0 +1,30 @@
+import js from '@eslint/js'
+import pluginVue from 'eslint-plugin-vue'
+import globals from 'globals'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  { ignores: ['dist', 'node_modules', 'coverage', 'internal', 'deploy'] },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  ...pluginVue.configs['flat/recommended'],
+  {
+    files: ['**/*.vue'],
+    languageOptions: { parserOptions: { parser: tseslint.parser } },
+  },
+  {
+    files: ['**/*.{ts,vue,js}'],
+    languageOptions: { globals: { ...globals.browser, ...globals.node } },
+    rules: {
+      'vue/multi-word-component-names': 'off',
+      // Prettier owns formatting; shadcn-vue components also omit prop defaults on purpose.
+      'vue/max-attributes-per-line': 'off',
+      'vue/singleline-html-element-content-newline': 'off',
+      'vue/multiline-html-element-content-newline': 'off',
+      'vue/html-self-closing': 'off',
+      'vue/html-indent': 'off',
+      'vue/html-closing-bracket-newline': 'off',
+      'vue/require-default-prop': 'off',
+    },
+  },
+)