feat: fpw plugins, validation/crawl perf, WS stats, test DB isolation

- Add Free_Proxy_Website-style fpw_* plugins and register them
- Per-plugin crawl timeout (crawl_timeout_seconds=120); remove global crawl_timeout setting
- Validator: fix connect vs total timeout on save; SOCKS session LRU cache; drop redundant semaphore
- Validation handler uses single DB connection; batch upsert after crawl; WorkerPool put_nowait
- Remove unused max_retries from settings API/UI; settings maintenance SQL + init_db cleanup of deprecated keys
- WebSocket dashboard stats; ProxyList pool_filter and API alignment
- POST /api/proxies/delete-one for IPv6-safe deletes; task poll stops on 404
- pytest uses PROXYPOOL_DB_PATH=db/proxies.test.sqlite so tests do not wipe production DB
- .gitignore: explicit proxies.test.sqlite patterns; fix plugin_service ValidationException import

Made-with: Cursor

app/plugins/fpw_premproxy.py

@@ -0,0 +1,64 @@
+"""premproxy.com 列表页表格。"""
+import re
+from typing import List
+
+from bs4 import BeautifulSoup
+
+from app.core.plugin_system import ProxyRaw
+from app.plugins.base import BaseHTTPPlugin
+from app.core.log import logger
+
+
+class FpwPremproxyPlugin(BaseHTTPPlugin):
+    name = "fpw_premproxy"
+    display_name = "PremProxy"
+    description = "premproxy.com HTTP/SOCKS 列表页"
+
+    def __init__(self):
+        super().__init__()
+        self.urls = [
+            "https://premproxy.com/list/",
+            "https://premproxy.com/socks-list/",
+        ]
+
+    def _parse_html(self, html: str) -> List[ProxyRaw]:
+        soup = BeautifulSoup(html, "lxml")
+        results: List[ProxyRaw] = []
+        for tr in soup.find_all("tr"):
+            tds = tr.find_all("td")
+            if len(tds) < 2:
+                continue
+            ip = tds[0].get_text(strip=True)
+            port = tds[1].get_text(strip=True)
+            if not re.match(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", ip):
+                continue
+            if not port.isdigit() or not (1 <= int(port) <= 65535):
+                continue
+            row = tr.get_text(" ", strip=True).lower()
+            if "socks5" in row:
+                proto = "socks5"
+            elif "socks4" in row or "socks" in row:
+                proto = "socks4"
+            elif "https" in row:
+                proto = "https"
+            else:
+                proto = "http"
+            try:
+                results.append(ProxyRaw(ip, int(port), proto))
+            except ValueError:
+                continue
+        return results
+
+    async def crawl(self) -> List[ProxyRaw]:
+        merged: List[ProxyRaw] = []
+        htmls = await self.fetch_all(self.urls, timeout=12, retries=1)
+        for url, html in zip(self.urls, htmls):
+            if not html:
+                continue
+            batch = self._parse_html(html)
+            if batch:
+                merged.extend(batch)
+                logger.info(f"{self.display_name} {url}: {len(batch)} 条")
+        if merged:
+            logger.info(f"{self.display_name} 合计 {len(merged)} 条")
+        return merged