Fix empty proxy sources (empty pool), first-run bat, elite hint

- load_settings/sanitize_settings: treat sources=[] as invalid; restore defaults (all([]) was true)
- _build_pool: defensive default sources + clearer empty-fetch log; elite-only empty fetch message
- FirstRun_Build_And_Install.bat: Python check + setup_and_build.ps1
- README + test for empty sources sanitize

Made-with: Cursor

proxy_chain_manager/config.py

@@ -217,6 +217,10 @@ def sanitize_settings(s: Settings) -> tuple[Settings, bool]:
     except (TypeError, ValueError):
         s.validation_timeout_seconds = 12.0
         changed = True
+    # Empty list survives "all(isinstance…)" — would skip all fetches and yield an empty pool.
+    if not isinstance(s.sources, list) or not all(isinstance(x, str) for x in s.sources) or len(s.sources) == 0:
+        s.sources = list(Settings().sources)
+        changed = True
     return s, changed
 
 
@@ -240,8 +244,12 @@ def load_settings() -> Settings:
     for k, v in raw.items():
         if hasattr(s, k):
             setattr(s, k, v)
-    if not isinstance(s.sources, list) or not all(isinstance(x, str) for x in s.sources):
-        s.sources = Settings().sources
+    if (
+        not isinstance(s.sources, list)
+        or not all(isinstance(x, str) for x in s.sources)
+        or len(s.sources) == 0
+    ):
+        s.sources = list(Settings().sources)
     if s.obfuscation_mode not in OBFUSCATION_MODES:
         s.obfuscation_mode = "auto"
     if not isinstance(s.pinned_chain, list):

proxy_chain_manager/service.py

@@ -469,6 +469,14 @@ class ChainService:
                     timeout=55.0,
                 )
                 entries = normalize_entries(rows, s.prefer_elite)
+                if s.prefer_elite and rows and not entries:
+                    self._notify({
+                        "type": "log",
+                        "text": (
+                            f"Source returned {len(rows)} proxies but none marked “elite” — all skipped. "
+                            "Turn off “Elite proxies only” in Chain Builder if every fetch is empty."
+                        ),
+                    })
                 self._notify({"type": "log", "text": f"Fetched {len(entries)} from source."})
                 return entries
             except asyncio.TimeoutError:
@@ -478,13 +486,26 @@ class ChainService:
                 self._notify({"type": "log", "text": f"Fetch error: {e!s}"})
                 return []
 
-        results = await asyncio.gather(*(_fetch_one(u) for u in s.sources))
+        src_urls = list(s.sources) if s.sources else list(Settings().sources)
+        if not s.sources:
+            self._notify({
+                "type": "log",
+                "text": "Settings had no proxy sources — using built-in defaults (save Settings to persist).",
+            })
+        if not src_urls:
+            self._notify({"type": "log", "text": "No proxy source URLs configured — cannot build a pool."})
+            return []
+
+        results = await asyncio.gather(*(_fetch_one(u) for u in src_urls))
         raw_urls: list[str] = []
         for chunk in results:
             raw_urls.extend(chunk)
 
         if not raw_urls:
-            self._notify({"type": "log", "text": "No proxies fetched from any source!"})
+            self._notify({
+                "type": "log",
+                "text": "No proxies fetched from any source (check network, URLs, or turn off “Elite only” if every list is filtered empty).",
+            })
             return []
 
         # Deduplicate, remove blacklisted, shuffle before capping