Add best share analysis page, miner column, and UI improvements

- Best share page: hex + binary hash comparison against network target,
  per-bit coloring showing exactly which bits prevented a valid block,
  toggle between network diff at time of finding vs current diff
- Capture best share hash from ckpool logs with one-time backfill
- Persist network difficulty at time of best share for historical accuracy
- Add miner (worker) column to blocks table via coinbase address matching
- Truncate block hashes in table with full hash on hover
- Increase hashrate chart Y-axis to 7 ticks for better readability

ui/src/lib/PoolOverview.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { untrack } from "svelte";
   import { snap } from "../stores/snapshot.svelte";
+  import { selectBestShare } from "../stores/selection.svelte";
   import {
     formatHashrate,
     formatUptime,
@@ -115,11 +116,6 @@
     fetch("/api/admin/ack-best", { method: "POST" });
   }
 
-  // DEBUG: remove before shipping
-  function debugBest(): void {
-    localAcked = 0;
-    fetch("/api/admin/reset-ack-best", { method: "POST" });
-  }
 </script>
 
 <section class="grid-5">
@@ -149,11 +145,7 @@
       {/each}
     </div>
     <div class="best-inner">
-      <div class="stat-label">
-        Best share
-        <!-- DEBUG: remove before shipping -->
-        <button class="debug-btn" onclick={(e: MouseEvent) => { e.stopPropagation(); debugBest(); }}>test</button>
-      </div>
+      <div class="stat-label">Best share</div>
       <div class="stat-value">{formatDifficulty(data.best_diff)}</div>
       <div
         class="luck-sub"
@@ -167,7 +159,17 @@
       {#if bestGlow}
         <!-- svelte-ignore a11y_click_events_have_key_events -->
         <!-- svelte-ignore a11y_no_static_element_interactions -->
-        <div class="ack-btn" onclick={ackBest} title="Dismiss the new best share animation">Nice</div>
+        <div class="ack-btn" onclick={ackBest} title="Dismiss the new best share notification">Nice</div>
+      {/if}
+      {#if data.best_diff > 0}
+        <!-- svelte-ignore a11y_click_events_have_key_events -->
+        <!-- svelte-ignore a11y_no_static_element_interactions -->
+        <div class="inspect-btn" onclick={selectBestShare} title="Inspect best share hash and leading zeros">
+          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" width="14" height="14">
+            <circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/>
+          </svg>
+          Inspect
+        </div>
       {/if}
     </div>
   </div>
@@ -446,16 +448,27 @@
     transform: scale(1.05);
   }
 
-  .debug-btn {
-    font-size: 0.6rem;
-    padding: 0.1em 0.4em;
-    opacity: 0.3;
-    border-radius: 3px;
-    margin-left: 0.5em;
-    vertical-align: middle;
+  .inspect-btn {
+    display: flex;
+    align-items: center;
+    gap: 0.3em;
+    width: fit-content;
+    margin: 0.4em auto 0;
+    padding: 0.2em 0.7em;
+    font-size: 0.72rem;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.04em;
+    color: var(--fg-dim);
+    border: 1px solid var(--border);
+    border-radius: 5px;
+    cursor: pointer;
+    transition: color 0.2s, border-color 0.2s, background 0.2s;
   }
-  .debug-btn:hover {
-    opacity: 1;
+  .inspect-btn:hover {
+    color: var(--accent);
+    border-color: var(--accent);
+    background: var(--bg-hover);
   }
 
   .height-card {