feat: fix repetitive update available prompt

Task #58 completed by ClaudeQueue

ClaudeQueue

server/server.js

@@ -25,15 +25,46 @@ import { logger }       from 'hono/logger';
 import { spawnSync }    from 'node:child_process';
 import { createServer } from 'node:http';
 import { readFileSync }  from 'node:fs';
+import { createHash }    from 'node:crypto';
 import { initDb, upsertUser, recordVideoAccess, getUserData } from './db.js';
 
 const PORT        = parseInt(process.env.PORT || '3000', 10);
 const APP_VERSION = process.env.APP_VERSION || '1.0.0';
 const YTDLP       = process.env.YTDLP_PATH  || 'yt-dlp';
 
-// Stable tag for this server process — changes on every deploy/restart.
-// The frontend polls /api/version and reloads when the tag drifts.
-const BUILD_TAG = process.env.BUILD_TAG || Date.now().toString(36);
+// ----------------------------------------------------------------------------
+// BUILD_TAG — must be DETERMINISTIC across restarts of identical code.
+//
+// Previously this was `Date.now().toString(36)`, which changes every time the
+// process starts even if nothing was deployed (crash-loop, healthcheck
+// restart, container reschedule). The frontend's checkBuildTag() polls
+// /api/version and re-shows the "Update available" modal the instant the tag
+// drifts — so a restarting-but-unchanged server kept re-announcing an update
+// that never actually happened, and clicking "Refresh UI" (which itself
+// reloads the page and re-polls) never made the prompt go away for good.
+//
+// Fix: hash the actual served frontend files. Identical code → identical
+// hash → identical tag, no matter how many times the process restarts. A
+// real deploy (changed files) still produces a new tag as intended.
+// process.env.BUILD_TAG still wins if a CI pipeline already injects a git
+// SHA — that's an even better source of truth than a content hash.
+// ----------------------------------------------------------------------------
+function computeBuildTag() {
+  try {
+    const hash = createHash('sha256');
+    for (const file of ['app.js', 'sw.js', 'index.html', 'styles.css']) {
+      hash.update(readFileSync(`./public/${file}`));
+    }
+    return hash.digest('hex').slice(0, 12);
+  } catch {
+    // Frontend files not readable (e.g. unit tests run outside ./public) —
+    // fall back to a fixed tag rather than Date.now(), so it still never
+    // drifts spuriously between restarts.
+    return 'dev-build';
+  }
+}
+
+const BUILD_TAG = process.env.BUILD_TAG || computeBuildTag();
 
 const SEARCH_LIMIT  = 25;
 const CHANNEL_LIMIT = 60;