chore: sync upstream — performance, webmentions v2, OG v3

- _data: switch to cachedFetch wrapper (10s timeout + 4h watch cache)
- js/webmentions.js: owner reply threading, platform provenance badges, DOM dedup, Micropub reply support
- js/comments.js: owner detection, reply system, Alpine.store integration
- _includes/components/webmentions.njk: data-wm-* attrs, provenance badge slots, reply buttons
- _includes/components/comments.njk: owner-aware comment form, threaded replies
- widgets/toc.njk: Alpine.js tocScanner upgrade (replaces is-land/inline-JS)
- lib/og.js + og-cli.js: OG card v3 (light theme, avatar, batched spawn, DESIGN_VERSION=3)
- eleventy.config.js: hasOgImage cache, memoized date filters, batched OG/unfurl, post-build GC, YouTube check opt
- base.njk: Inter font preloads + toc-scanner.js script
- critical.css: font-face declarations (font-display:optional)
- tailwind.css: font-display swap→optional
- tailwind.config.js: prose link colors -700→-600
- Color design system: accent-700/300 → accent-600/400 across components

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

changelog.njk

@@ -18,7 +18,7 @@ withSidebar: false
     <template x-for="tab in tabs" :key="tab.key">
       <button
         @click="activeTab = tab.key"
-        :class="activeTab === tab.key ? 'border-b-2 border-accent-500 text-accent-700 dark:text-accent-300' : 'text-surface-600 dark:text-surface-400 hover:text-surface-700 dark:hover:text-surface-300'"
+        :class="activeTab === tab.key ? 'border-b-2 border-accent-500 text-accent-600 dark:text-accent-400' : 'text-surface-600 dark:text-surface-400 hover:text-surface-700 dark:hover:text-surface-300'"
         :aria-selected="(activeTab === tab.key).toString()"
         role="tab"
         class="flex items-center gap-1.5 px-3 py-2 text-sm font-medium transition-colors -mb-px whitespace-nowrap flex-shrink-0"
@@ -53,7 +53,7 @@ withSidebar: false
         <li class="bg-surface-50 dark:bg-surface-800 border border-surface-200 dark:border-surface-700 rounded-lg p-4 shadow-sm">
           <div class="flex items-start gap-3">
             <a :href="commit.url" target="_blank" rel="noopener"
-               class="font-mono text-xs bg-surface-100 dark:bg-surface-800 px-1.5 py-0.5 rounded text-accent-700 dark:text-accent-300 hover:underline flex-shrink-0 mt-0.5"
+               class="font-mono text-xs bg-surface-100 dark:bg-surface-800 px-1.5 py-0.5 rounded text-accent-600 dark:text-accent-400 hover:underline flex-shrink-0 mt-0.5"
                x-text="commit.sha"></a>
             <div class="min-w-0 flex-1">
               <p class="text-sm font-medium text-surface-900 dark:text-surface-100 break-words" x-text="commit.title"></p>
@@ -64,7 +64,7 @@ withSidebar: false
                   x-text="categoryLabels[commit.category] || commit.category"
                 ></span>
                 <a :href="commit.repoUrl" target="_blank" rel="noopener"
-                   class="text-xs px-2 py-0.5 rounded-full bg-surface-100 dark:bg-surface-800 text-surface-600 dark:text-surface-400 hover:text-accent-700 dark:hover:text-accent-300"
+                   class="text-xs px-2 py-0.5 rounded-full bg-surface-100 dark:bg-surface-800 text-surface-600 dark:text-surface-400 hover:text-accent-600 dark:hover:text-accent-400"
                    x-text="commit.repoName"></a>
                 <span class="text-xs text-surface-600 dark:text-surface-400 font-mono" x-text="formatDate(commit.date)"></span>
                 <span class="text-xs text-surface-600 dark:text-surface-400" x-text="'by ' + commit.author"></span>
@@ -118,32 +118,34 @@ function changelogApp() {
 
     tabs: [
       { key: 'all', label: 'All' },
-      { key: 'features', label: 'Features' },
-      { key: 'fixes', label: 'Fixes' },
-      { key: 'performance', label: 'Performance' },
-      { key: 'accessibility', label: 'Accessibility' },
-      { key: 'documentation', label: 'Docs' },
-      { key: 'style', label: 'Style' },
-      { key: 'other', label: 'Other' },
+      { key: 'core', label: 'Core' },
+      { key: 'deployment', label: 'Deployment' },
+      { key: 'theme', label: 'Theme' },
+      { key: 'endpoints', label: 'Endpoints' },
+      { key: 'syndicators', label: 'Syndicators' },
+      { key: 'post-types', label: 'Post Types' },
+      { key: 'presets', label: 'Presets' },
     ],
 
     categoryLabels: {
-      features: 'Features',
-      fixes: 'Fixes',
-      performance: 'Performance',
-      accessibility: 'Accessibility',
-      documentation: 'Docs',
-      style: 'Style',
+      core: 'Core',
+      deployment: 'Deployment',
+      theme: 'Theme',
+      endpoints: 'Endpoint',
+      syndicators: 'Syndicator',
+      'post-types': 'Post Type',
+      presets: 'Preset',
       other: 'Other',
     },
 
     categoryColors: {
-      features: 'bg-green-100 dark:bg-green-900 text-green-700 dark:text-green-300',
-      fixes: 'bg-orange-100 dark:bg-orange-900 text-orange-700 dark:text-orange-300',
-      performance: 'bg-blue-100 dark:bg-blue-900 text-blue-700 dark:text-blue-300',
-      accessibility: 'bg-purple-100 dark:bg-purple-900 text-purple-700 dark:text-purple-300',
-      documentation: 'bg-yellow-100 dark:bg-yellow-900 text-yellow-700 dark:text-yellow-300',
-      style: 'bg-pink-100 dark:bg-pink-900 text-pink-700 dark:text-pink-300',
+      core: 'bg-blue-100 dark:bg-blue-900 text-blue-700 dark:text-blue-300',
+      deployment: 'bg-orange-100 dark:bg-orange-900 text-orange-700 dark:text-orange-300',
+      theme: 'bg-purple-100 dark:bg-purple-900 text-purple-700 dark:text-purple-300',
+      endpoints: 'bg-green-100 dark:bg-green-900 text-green-700 dark:text-green-300',
+      syndicators: 'bg-teal-100 dark:bg-teal-900 text-teal-700 dark:text-teal-300',
+      'post-types': 'bg-pink-100 dark:bg-pink-900 text-pink-700 dark:text-pink-300',
+      presets: 'bg-yellow-100 dark:bg-yellow-900 text-yellow-700 dark:text-yellow-300',
       other: 'bg-surface-100 dark:bg-surface-800 text-surface-700 dark:text-surface-300',
     },
 
@@ -156,37 +158,11 @@ function changelogApp() {
       await this.fetchChangelog(30);
     },
 
-    async fetchJson(paths) {
-      for (const path of paths) {
-        try {
-          const response = await fetch(path);
-          if (response.ok) {
-            return {
-              ok: true,
-              data: await response.json(),
-            };
-          }
-        } catch {
-          // Try next candidate path.
-        }
-      }
-
-      return {
-        ok: false,
-        data: null,
-      };
-    },
-
     async fetchChangelog(days) {
       try {
-        const result = await this.fetchJson([
-          '/github/api/changelog?days=' + days,
-          '/githubapi/api/changelog?days=' + days,
-        ]);
-
-        if (!result.ok) throw new Error('Failed to fetch');
-
-        const data = result.data || {};
+        const response = await fetch('/githubapi/api/changelog?days=' + days);
+        if (!response.ok) throw new Error('Failed to fetch');
+        const data = await response.json();
         this.commits = data.commits || [];
         this.categories = data.categories || {};
         this.currentDays = data.days;