feat: initial Speedboard implementation

sitespeed.io web UI with Express/Pug/SQLite — port 3132.
Includes job queue, SSE live log, full metrics dashboard,
site history, CO2/axe/CWV sections, and Docker support.

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

views/partials/timings.pug

@@ -0,0 +1,23 @@
+- function ms(v) { return v != null ? v.toFixed(0)+' ms' : '—'; }
+- const rows = [
+-   ['Page Load Time', job.page_load_time],
+-   ['Fully Loaded', job.fully_loaded],
+-   ['DOM Content Loaded', job.dom_content_loaded],
+-   ['DOM Interactive', job.dom_interactive],
+-   ['Speed Index', job.speed_index],
+-   ['First Visual Change', job.first_visual_change],
+-   ['Last Visual Change', job.last_visual_change],
+-   ['Visual Complete 85%', job.visual_complete_85],
+-   ['Perceptual Speed Index', job.perceptual_speed_index],
+-   ['Front End Time', job.front_end_time],
+-   ['Back End Time', job.back_end_time],
+-   ['Max Potential FID', job.max_potential_fid],
+- ]
+
+div(class='bg-white border border-gray-200 rounded-xl p-5')
+  h2(class='text-base font-semibold mb-4') Navigation & Visual Timings
+  div(class='grid grid-cols-2 sm:grid-cols-3 gap-2')
+    each row in rows
+      div(class='bg-gray-50 rounded-lg px-3 py-2 flex justify-between items-center')
+        span(class='text-xs text-gray-500')= row[0]
+        span(class='text-sm font-semibold')= ms(row[1])