Root cause of the intermittent white screen: the shell HTML is no-cache
(cf-cache-status: DYNAMIC), so every page-open does a synchronous round-trip
to the residential origin before any pixel renders — and the SW's network-first
navigation only fell back to the cached shell on REJECTION, never on slowness.
A stalled fetch meant staring at white with a perfectly good shell in cache.
The boot seatbelt couldn't see it either: it lives inside the HTML that hadn't
arrived yet, so slow boots left no telemetry.
- service-worker: race navigation fetch vs 2.5s grace timer. Network wins →
fresh HTML as before; timer/5xx/failure → cached shell instantly, network
response still refreshes the cache in the background. Safe due to the 14-day
immutable-chunk grace window. Caps the white screen at ~2.5s for repeat
visitors on any network.
- app.html: beacon `boot-slow: Nms (html Nms) on 4g` when mount takes >4s —
the "white screen, then it loaded" glitches finally leave a trace, with
HTML-arrival timing to separate slow-origin from slow-JS.
- admin: bot UAs (HeadlessChrome/bot/spider/crawl/…) excluded from the
headline "Load errors today" count — throttled crawlers trip the 10s boot
check routinely (the one recorded error was HeadlessChrome on X11, not a
phone). Bots stay visible in the list, tagged + dimmed.
Tests: telemetry test extended for bot flag + filtered counts. 223 pytest +
11 vitest green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The post-deploy blank/slow load: new hashed chunks weren't in Cloudflare yet, so
the first visitor pulled them cold from the residential origin — AND the service
worker simultaneously precached ~30 of those cold assets (a request storm),
pushing past the 7s boot timeout.
* sync-static.sh now warms the CF edge cache (fetches every immutable asset
through the public domain) so the first visitor gets HITs, not cold-origin.
* Service worker no longer bulk-precaches on install (the browser already caches
immutable assets for a year); it caches the shell + assets lazily as used. No
more storm.
* Boot-recovery timeout 7s → 10s so a merely-slow load doesn't flash the card.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Root cause (SPA mode, fallback: index.html): the SW precached build+files but
NEVER the shell HTML, so its navigation fallback `caches.match('/')` resolved to
nothing — any failed navigation fetch (transient WAN/CF blip) returned an empty
response → blank white screen.
Fix: precache `/` on install, and on every successful navigation keep the
freshest *real 200 text/html* response as the cached shell; on a failed fetch,
serve that cached shell instead of blank. Also expanded the server-owned path
exclusions (the SW now passes through /docs, /openapi.json, /healthz, /today,
/sitemap.xml in addition to /api/ and /a/) so it never caches non-SPA responses
as the shell.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two calm returning-reader features.
Since-last-visit (Highlights companion, not a nav lane — per Codex):
* queries.feed gains a `since` filter; GET /api/since?ts= returns the count +
a few accepted/non-dup/visible articles discovered since the reader's last
visit (boundary-respecting; invalid/future ts → 0, no error).
* Home stores last_seen in localStorage (reads prev, then stamps now); on
Highlights, a gentle "Since you were last here, N new calm reads came in"
note with a "See what's new" reveal of a compact inline section. Dismissible.
No badges, no unread counts, no "missed" language.
PWA:
* Real PNG icons (192/512 + full-bleed maskable) rasterized from favicon.svg;
manifest fixed (azure theme to match the brand, PNG icons); apple-touch-icon.
* Minimal service worker: precache the app shell, always-fresh API + /a/ pages.
* Gentle, dismissible install banner (beforeinstallprompt → Install; iOS → the
Share → Add to Home Screen hint). Never nags.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
thejayman77