fix: try https fallback when http port 80 is closed (fixes HTTPS-only domains marked as dead)

Many modern servers refuse HTTP connections entirely. The validator was
only trying http://, causing HTTPS-only sites to be wrongly marked dead.
Now falls back to https:// on ConnectError. Also increased timeouts slightly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/validator.py

@@ -85,27 +85,29 @@ async def _check_domain(domain: str) -> dict:
         "load_time_ms":     None,
     }
     t0 = time.monotonic()
+
+    # Try http first (follows http→https redirects automatically).
+    # Fall back to https directly if port 80 is closed/refused — many modern
+    # servers only listen on 443 and would be wrongly marked dead otherwise.
+    for scheme in ("http", "https"):
         try:
             async with httpx.AsyncClient(
-            timeout=httpx.Timeout(connect=5, read=8, write=5, pool=10),
+                timeout=httpx.Timeout(connect=7, read=12, write=5, pool=15),
                 follow_redirects=True,
                 headers=_HEADERS,
                 verify=False,
                 max_redirects=5,
             ) as client:
-            resp = await client.get(f"http://{domain}")
+                resp = await client.get(f"{scheme}://{domain}")
 
             result["load_time_ms"] = int((time.monotonic() - t0) * 1000)
             result["status_code"]  = resp.status_code
             result["server"]       = (resp.headers.get("server") or "")[:100]
-
-        # Resolve IP for live-looking domains
             result["ip"]           = await _resolve_ip(domain)
 
             final_url  = str(resp.url)
             final_host = urlparse(final_url).netloc.lower().lstrip("www.")
 
-        # Redirected to a different root domain?
             if not _same_domain(domain, final_url):
                 for ph in PARKING_REDIRECT_HOSTS:
                     if ph in final_host:
@@ -126,8 +128,14 @@ async def _check_domain(domain: str) -> dict:
             result["prescreen_status"] = "live"
             return result
 
+        except httpx.ConnectError:
+            # Port closed / connection refused — try the other scheme
+            logger.debug("Validator %s: ConnectError on %s, trying next scheme", domain, scheme)
+            continue
         except Exception as e:
-        logger.debug("Validator %s: %s", domain, e)
+            logger.debug("Validator %s (%s): %s", domain, scheme, e)
+            break  # timeout or other error — don't retry
+
     result["load_time_ms"] = int((time.monotonic() - t0) * 1000)
     return result