Add a page which proves the best share PoW

ui/src/App.svelte

@@ -14,6 +14,7 @@
   import AcceleratorPage from "./lib/AcceleratorPage.svelte";
   import StatsPage from "./lib/StatsPage.svelte";
   import BestSharePage from "./lib/BestSharePage.svelte";
+  import SharePowPage from "./lib/SharePowPage.svelte";
   import SharesBar from "./lib/SharesBar.svelte";
   import BlockFoundAnimation from "./lib/BlockFoundAnimation.svelte";
   import QRCode from "qrcode";
@@ -64,6 +65,12 @@
         <BestSharePage />
       </div>
     {/key}
+  {:else if selection.page === "bestshare-pow"}
+    {#key 'bestshare-pow'}
+      <div class="page-enter">
+        <SharePowPage />
+      </div>
+    {/key}
   {:else if selection.worker}
     {#key selection.worker}
       <div class="page-enter">

ui/src/lib/BestSharePage.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { clearSelection } from "../stores/selection.svelte";
+  import { clearSelection, selectBestSharePow } from "../stores/selection.svelte";
   import { snap } from "../stores/snapshot.svelte";
   import { formatDifficulty } from "../format";
 
@@ -179,6 +179,19 @@
     <button type="button" class="back" onclick={clearSelection}>
       &larr; Back to dashboard
     </button>
+    <button
+      type="button"
+      class="pow-btn"
+      onclick={selectBestSharePow}
+      title="Show the block header and raw data that reproduce this share's proof of work"
+    >
+      <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" width="14" height="14">
+        <path d="M21 16V8a2 2 0 0 0-1-1.73l-7-4a2 2 0 0 0-2 0l-7 4A2 2 0 0 0 3 8v8a2 2 0 0 0 1 1.73l7 4a2 2 0 0 0 2 0l7-4A2 2 0 0 0 21 16z"/>
+        <polyline points="3.27 6.96 12 12.01 20.73 6.96"/>
+        <line x1="12" y1="22.08" x2="12" y2="12"/>
+      </svg>
+      Show PoW
+    </button>
   </nav>
 
   <header class="head">
@@ -350,6 +363,10 @@
   }
   .crumbs {
     margin-bottom: 0.25rem;
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    gap: 0.75rem;
   }
   .back {
     font: inherit;
@@ -365,6 +382,23 @@
     border-color: var(--accent);
     background: var(--bg-hover);
   }
+  .pow-btn {
+    font: inherit;
+    display: inline-flex;
+    align-items: center;
+    gap: 0.45em;
+    color: var(--accent);
+    background: transparent;
+    border: 1px solid var(--accent-dim);
+    border-radius: 6px;
+    padding: 0.4em 0.85em;
+    cursor: pointer;
+  }
+  .pow-btn:hover {
+    border-color: var(--accent);
+    background: var(--bg-hover);
+    text-shadow: 0 0 8px rgba(255, 122, 58, 0.4);
+  }
 
   /* Difficulty view toggle */
   .toggle-bar {

ui/src/stores/selection.svelte.ts

@@ -14,6 +14,7 @@ const WORKER_PREFIX = "#/worker/";
 const ACCELERATOR_HASH = "#/accelerator";
 const STATS_HASH = "#/stats";
 const BESTSHARE_HASH = "#/bestshare";
+const BESTSHARE_POW_HASH = "#/bestshare/pow";
 
 type Selection = { user: string | null; worker: string | null; page: string | null };
 
@@ -28,6 +29,9 @@ function readHash(): Selection {
   if (h === STATS_HASH) {
     return { user: null, worker: null, page: "stats" };
   }
+  if (h === BESTSHARE_POW_HASH) {
+    return { user: null, worker: null, page: "bestshare-pow" };
+  }
   if (h === BESTSHARE_HASH) {
     return { user: null, worker: null, page: "bestshare" };
   }
@@ -73,6 +77,10 @@ export function selectBestShare(): void {
   window.location.hash = BESTSHARE_HASH;
 }
 
+export function selectBestSharePow(): void {
+  window.location.hash = BESTSHARE_POW_HASH;
+}
+
 export function clearSelection(): void {
   window.location.hash = "";
 }

ui/src/types.ts

@@ -113,6 +113,26 @@ export type HashratePoint = {
   v: number; // H/s
 };
 
+// PoW reproduction data for the best share seen since ckpool patch 0008
+// went live (logged by ckpool, ingested from the log by kamado-api).
+// `header` is the raw 80-byte block header in hashing byte order —
+// double-SHA256 it and reverse the digest to get `hash`. `coinbase` plus
+// `merklebranches` reproduce the merkle root committed in the header.
+export type BestSharePow = {
+  sdiff: number;
+  netdiff: number;
+  height: number;
+  hash: string; // display-order (big-endian) block header hash
+  header: string; // 160 hex chars
+  coinbase: string; // full serialized coinbase tx, hex
+  cb1len: number; // bytes preceding extranonce1 within the coinbase
+  merklebranches: string[] | null;
+  enonce1: string;
+  nonce2: string;
+  workername: string;
+  seen_at: string; // RFC 3339, when kamado-api ingested the record
+};
+
 // One entry per ckpool serverurl[] bind, declared by the deployment via
 // the STRATUM_SERVERS env. `kind` is the stable tag the UI switches on;
 // `label` is free text shown on hover.
@@ -137,6 +157,11 @@ export type Snapshot = {
   best_diff: number;
   best_share_hash?: string;
   best_share_net_diff?: number;
+  // Full header/coinbase/merkle-branch record for the best share seen
+  // since ckpool patch 0008 was deployed. May describe a lower-diff
+  // share than best_diff when the all-time best predates the patch —
+  // compare hashes and disclose.
+  best_share_pow?: BestSharePow;
   acked_best_diff: number;
   cumulative_shares: number;
   next_block_reward_btc: number;