Add per-worker stats page with cumulative work and luck

Expose ckpool's per-worker cumulative shares via patch 0004, add a
WorkerDetailPage with hashrate, status, best share with per-worker luck
(bestever/shares*100), and total work with pool share percentage.
Worker names are now clickable in MinersTable and UserDetailPage.
Also centers numeric columns below their headers.

ui/src/lib/UserDetailPage.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
   import { snap } from "../stores/snapshot.svelte";
-  import { selection, clearSelection } from "../stores/selection.svelte";
+  import { selection, clearSelection, selectWorker } from "../stores/selection.svelte";
   import {
     formatHashrate,
     formatDifficulty,
@@ -223,7 +223,12 @@
               <tr class:offline={!r.online} class:idle={r.idle}>
                 <td>
                   <div class="wname mono">
-                    {r.worker}
+                    <button
+                      type="button"
+                      class="worker-btn"
+                      onclick={() => selectWorker(r.worker)}
+                      title="View per-worker stats"
+                    >{r.worker}</button>
                     {#if r.tls}
                       <span class="badge tls" title="Connected via TLS">
                         <svg viewBox="0 0 16 16" aria-hidden="true">
@@ -350,6 +355,23 @@
     gap: 0.4em;
     flex-wrap: wrap;
   }
+  .worker-btn {
+    font: inherit;
+    color: inherit;
+    background: transparent;
+    border: none;
+    padding: 0;
+    cursor: pointer;
+    text-align: left;
+    border-bottom: 1px dashed transparent;
+    transition: color 0.15s, border-bottom-color 0.15s;
+  }
+  .worker-btn:hover,
+  .worker-btn:focus-visible {
+    color: var(--accent);
+    border-bottom-color: var(--accent);
+    outline: none;
+  }
   .src-ip {
     color: var(--fg-dim);
     font-size: 0.75em;