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.

src/components/ProjectList.vue

@@ -0,0 +1,91 @@
+<script setup lang="ts">
+import { faCodePullRequest, faCircleDot, faGears } from '@fortawesome/free-solid-svg-icons'
+import { FontAwesomeIcon } from '@fortawesome/vue-fontawesome'
+import { ageSince, isZeroTime } from '@/lib/format'
+import type { Repo } from '@/lib/types'
+
+defineProps<{ repos: Repo[]; total: number; focused: string | null; nowMs: number }>()
+defineEmits<{ select: [fullName: string] }>()
+
+const DOT = { crit: 'bg-crit', warn: 'bg-warn', ok: 'bg-ok' } as const
+const LABEL = { crit: 'Critical', warn: 'Warning', ok: 'Healthy' } as const
+</script>
+
+<template>
+  <section aria-labelledby="projects-title">
+    <h2 id="projects-title" class="mb-4 text-lg font-semibold tracking-tight">
+      Projects
+      <span class="text-muted-foreground text-sm font-normal" data-test="project-count">{{
+        repos.length === total ? total : `${repos.length} of ${total}`
+      }}</span>
+    </h2>
+    <p
+      v-if="repos.length === 0"
+      class="text-muted-foreground border-border rounded-lg border border-dashed p-4 text-sm"
+      data-test="no-projects"
+    >
+      No projects match the search.
+    </p>
+    <ul v-else class="border-border bg-surface divide-border divide-y rounded-lg border">
+      <li
+        v-for="repo in repos"
+        :key="repo.fullName"
+        class="px-3 py-2.5"
+        :class="focused === repo.fullName ? 'bg-accent' : ''"
+        data-test="project"
+      >
+        <div class="flex items-center gap-2.5">
+          <span class="size-2 shrink-0 rounded-full" :class="DOT[repo.health]"></span>
+          <span class="sr-only">{{ LABEL[repo.health] }}:</span>
+          <button
+            type="button"
+            class="hover:text-link min-w-0 flex-1 truncate text-left text-sm font-medium"
+            :aria-pressed="focused === repo.fullName"
+            @click="$emit('select', repo.fullName)"
+          >
+            {{ repo.fullName.split('/')[1] }}
+            <span class="text-muted-foreground font-normal">{{ repo.fullName.split('/')[0] }}</span>
+          </button>
+          <a
+            v-if="repo.release"
+            :href="repo.release.url"
+            class="text-muted-foreground hover:text-link font-mono text-xs"
+          >
+            {{ repo.release.tag }}
+          </a>
+          <a v-else :href="repo.releasesUrl" class="text-muted-foreground hover:text-link text-xs"
+            >no release</a
+          >
+        </div>
+        <div
+          class="text-muted-foreground mt-1 flex items-center gap-4 pl-[18px] text-xs tabular-nums"
+        >
+          <a
+            :href="`${repo.url}/actions`"
+            class="hover:text-link flex items-center gap-1.5"
+            :class="repo.workflows.failing ? 'text-crit' : ''"
+          >
+            <FontAwesomeIcon :icon="faGears" aria-hidden="true" />
+            {{
+              repo.workflows.failing
+                ? `${repo.workflows.failing}/${repo.workflows.total} failing`
+                : repo.workflows.total
+            }}
+            <span class="sr-only">workflows</span>
+          </a>
+          <a :href="`${repo.url}/pulls`" class="hover:text-link flex items-center gap-1.5">
+            <FontAwesomeIcon :icon="faCodePullRequest" aria-hidden="true" />{{ repo.prs.open }}
+            <span class="sr-only">pull requests</span>
+          </a>
+          <a :href="`${repo.url}/issues`" class="hover:text-link flex items-center gap-1.5">
+            <FontAwesomeIcon :icon="faCircleDot" aria-hidden="true" />{{ repo.issues.open }}
+            <span class="sr-only">issues</span>
+          </a>
+          <span v-if="repo.release && !isZeroTime(repo.release.publishedAt)" class="ml-auto">
+            released {{ ageSince(repo.release.publishedAt, nowMs) }} ago
+          </span>
+        </div>
+      </li>
+    </ul>
+  </section>
+</template>