fetch: detect proxy protocol from source URL path

- detect_proto_from_path() infers socks4/socks5/http from URL
- extract_proxies() now returns (address, proto) tuples
- ppf.py updated to handle protocol-tagged proxies
- profiler signal handler for SIGTERM stats dump

fetch.py

@@ -191,17 +191,47 @@ def is_known_proxy(proxy):
     """Check if proxy is in known cache."""
     return proxy in _known_proxies
 
-def extract_proxies(content, proxydb=None, filter_known=True):
+def detect_proto_from_path(url):
+    """Detect proxy protocol from URL path.
+
+    Many proxy lists indicate protocol in their path:
+    - /socks5/, /socks5.txt, socks5-proxies.txt -> socks5
+    - /socks4/, /socks4a/, /socks4.txt -> socks4
+    - /http/, /http.txt, http-proxies.txt -> http
+    - /https/, /ssl/ -> http (HTTPS proxies use HTTP CONNECT)
+
+    Args:
+        url: Source URL path or full URL
+
+    Returns:
+        Protocol string ('http', 'socks4', 'socks5') or None if not detected
+    """
+    url_lower = url.lower()
+    # Check for socks5 indicators
+    if 'socks5' in url_lower:
+        return 'socks5'
+    # Check for socks4/socks4a indicators
+    if 'socks4' in url_lower:
+        return 'socks4'
+    # Check for http/https/ssl/connect indicators
+    if any(x in url_lower for x in ('/http', 'http-', 'http_', 'http.', '/https', '/ssl', '/connect')):
+        return 'http'
+    return None
+
+
+def extract_proxies(content, proxydb=None, filter_known=True, proto=None):
     """Extract and normalize proxy addresses from content.
 
     Args:
         content: HTML/text content to parse
         proxydb: Database connection for known proxy lookup (optional)
         filter_known: If True, filter out known proxies and return new only
+        proto: Protocol to assign to all extracted proxies (from source URL)
 
     Returns:
         If filter_known: (unique_count, new_proxies) tuple
-        If not filter_known: list of all unique valid proxies
+            new_proxies is list of (address, proto) tuples
+        If not filter_known: list of (address, proto) tuples
     """
     matches = re.findall(r'([0-9]+(?:\.[0-9]+){3}:[0-9]{2,5})[\D$]', cleanhtml(content))
 
@@ -215,7 +245,7 @@ def extract_proxies(content, proxydb=None, filter_known=True):
         p = '%s:%s' % (ip, port)
         uniques_dict[p] = True
 
-    uniques = [p for p in uniques_dict.keys() if is_usable_proxy(p)]
+    uniques = [(p, proto) for p in uniques_dict.keys() if is_usable_proxy(p)]
 
     if not filter_known:
         return uniques
@@ -225,9 +255,9 @@ def extract_proxies(content, proxydb=None, filter_known=True):
         init_known_proxies(proxydb)
 
     new = []
-    for p in uniques:
+    for p, pr in uniques:
         if not is_known_proxy(p):
-            new.append(p)
+            new.append((p, pr))
             add_known_proxies([p])
 
     return len(uniques), new