Add per-story views, trending, and reader reading-experience upgrades

Surface read counts and sharpen the reader:
- story_views table + RecordStoryView on /api/article (background,
  filter-guarded); "Popular this week" home rail via TrendingStories;
  read-count badge and reading-time chip decorated onto every listing
- reader: signed-in-only read-aloud (TTS), native share/copy, and an
  Aa typography popover (size/serif/sepia) persisted per device
- real alt text on card/reader/related/search images; time-of-day Pete
  greeting on the home hero
- harden exec() to skip (not panic) on a nil DB so background writes
  can't crash on a closed handle

Tests: story_views_test.go, trending_test.go. Suite green, CSS rebuilt.

internal/web/templates/index.html

@@ -13,10 +13,31 @@
     Pete reads RSS and sorts stories into channels, fresh from his feeds.
     {{end}}
   </p>
+  <p class="mx-auto mt-5 inline-flex items-center gap-2 rounded-full bg-[color:var(--card)] px-4 py-2 text-sm font-semibold shadow-pete border-2 border-[color:var(--ink)]/10">
+    <img src="/static/img/pete.avif" alt="Pete" width="24" height="24"
+         class="h-6 w-6 rounded-full object-cover">
+    <span data-pete-greeting>Hey, I'm Pete. Here's what's new.</span>
+  </p>
 </section>
 
 <section data-weather-card class="mb-10 empty:hidden"></section>
 
+{{if .Trending}}
+<section class="mb-10">
+  <div class="flex items-end justify-between gap-3 mb-4">
+    <h2 class="font-display text-xl sm:text-2xl font-bold">
+      <span aria-hidden="true">🔥</span> Popular this week
+    </h2>
+    <span class="text-xs text-[color:var(--ink)]/50">what readers are opening most</span>
+  </div>
+  <div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-4">
+    {{range .Trending}}
+      {{template "card" dict "Story" . "Theme" .Channel "ShowChannel" true}}
+    {{end}}
+  </div>
+</section>
+{{end}}
+
 {{if .ForYou}}
 <section class="mb-10">
   <div class="flex items-end justify-between gap-3 mb-4">
@@ -104,7 +125,7 @@
   </div>
   {{else}}
   <div class="rounded-3xl bg-[color:var(--card)] border-2 border-dashed border-[color:var(--ink)]/15 p-8 text-center text-[color:var(--ink)]/60">
-    Nothing here yet — Pete's still listening.
+    Nothing here yet. Pete's still listening for the first story.
   </div>
   {{end}}
 </section>