Merge History into Log Eggs page; update dashboard card order and colors

- Removed standalone History page (history.html); full collection history
  (date filter, edit, delete, totals footer) is now embedded in the Log
  Eggs page below the log form
- Removed History nav link from all pages
- Reordered dashboard stat cards: egg counts → averages → Flock Size →
  cost cards
- Egg count and average cards now use green; Flock Size card uses orange
- Updated README to reflect removed History page, merged log/history
  feature, dashboard card changes, and project structure

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

nginx/html/flock.html

@@ -13,7 +13,6 @@
         <ul class="nav-links">
             <li><a href="/">Dashboard</a></li>
             <li><a href="/log">Log Eggs</a></li>
-            <li><a href="/history">History</a></li>
             <li><a href="/flock">Flock</a></li>
             <li><a href="/budget">Budget</a></li>
             <li><a href="/summary">Summary</a></li>