UI pass: nav state, ears, feeds table, font flash, faster navigation

- Issue pages highlight Archive instead of Latest unless the issue is the
  newest one (IssueView::is_latest), with a router test.
- The ears row is empty by default and says "Dashboard" on dashboard pages;
  "Morning edition" only survives on the empty-state hero.
- Run page: the Feeds card table is fixed-layout and truncates long feed
  names with the full title on hover instead of pushing the entries column
  out of the card.
- Static assets are content-hashed, so serve them immutable for a year;
  preload both Newsreader faces and use font-display: block so a cache
  revalidation never paints the fallback serif first. Persisted details
  state is restored pre-paint from theme.js.
- Cross-document view transitions (140 ms fade, masthead held still) and
  Speculation Rules (prerender reader pages, prefetch dashboard pages on
  hover) served from /static/speculation.json via the Speculation-Rules
  header, which the CSP would otherwise block inline. No client router.
- Dashboard nav gets the same accent underline as the site nav; 40 px
  targets for the theme toggle, account link and dashboard nav.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MD4VWGq6mGcd8Bg67qyx9k

src/web/public.rs

@@ -219,8 +219,9 @@ pub async fn show_issue(
         let response = issue::render_full(&state, view, viewer, &session).await?;
         return Ok(public_cache(response, &headers));
     }
+    let active_nav = if view.is_latest { "latest" } else { "archive" };
     let response = Html(IssuePublicTemplate {
-        page: Page::new(format!("Issue {date}"), None, "latest"),
+        page: Page::new(format!("Issue {date}"), None, active_nav),
         issue: PublicIssue::from(&view.issue),
         downloads: Vec::new(),
         empty: false,