Prod debug (ssh, headless=True + mobileproxy): the camoufox fetch was returning
a 274KB generic avito shell with 0 listings — NOT a block/captcha (no
captcha/datadome/firewall markers, status 200, correct final_url). Avito hydrates
the SERP listings into the DOM client-side AFTER domcontentloaded; at the 2500ms
wait the page.content() snapshot still had only the generic shell. At 5-6s it's
the full SERP: 3.2MB, priceDetailed=50.
Fix: BROWSER_WAIT_MS default 2500→6000 (5s proven full + 1s margin), config.py
browser_wait_ms 2500→6000 to match. The whole camoufox+proxy migration works —
this was the last blocker. NOT headless detection (headless=True returns real
data); the abandoned xvfb/headless=virtual change is unnecessary.
Refs #905, #883
