Fix snap chromium path collapsing to /usr/bin/snap

readlink/realpath of /snap/bin/chromium becomes /usr/bin/snap, which is
not a browser and breaks DrissionPage launch. Keep the snap wrapper path,
reject snap host basenames, and prefer real deb chromium binaries.

grok_register_ttk.py

@@ -781,7 +781,9 @@ def apply_headless_to_options(options, headless: bool = True) -> None:
 CHROMIUM_CANDIDATES = (
     "/usr/bin/chromium",
     "/usr/bin/chromium-browser",
-    "/snap/bin/chromium",
+    "/usr/lib/chromium/chromium",
+    "/usr/lib/chromium-browser/chromium-browser",
+    "/snap/bin/chromium",  # keep as /snap/bin/chromium — do NOT resolve to /usr/bin/snap
 )
 CHROME_CANDIDATES = (
     "/usr/bin/google-chrome-stable",
@@ -816,17 +818,94 @@ STEALTH_INIT_JS = r"""
 })();
 """
 
+# Paths that look like snap host / shell wrappers, not a browser binary.
+_INVALID_BROWSER_BASENAMES = frozenset(
+    {
+        "snap",
+        "snap-confine",
+        "snapd",
+        "env",
+        "bash",
+        "sh",
+        "python",
+        "python3",
+        "uv",
+    }
+)
+
+
 def _is_google_chrome_path(path: str | None) -> bool:
     if not path:
         return False
     base = os.path.basename(path)
-    return "chrome" in base and "chromium" not in path
+    # /usr/bin/snap is NOT chrome
+    if base in _INVALID_BROWSER_BASENAMES:
+        return False
+    return "chrome" in base and "chromium" not in path.lower()
+
+
+def _looks_like_browser_path(path: str | None) -> bool:
+    """Reject snap host binary etc. Accept chromium/chrome paths only."""
+    if not path:
+        return False
+    if not (os.path.isfile(path) or os.path.islink(path)):
+        return False
+    base = os.path.basename(path)
+    if base in _INVALID_BROWSER_BASENAMES:
+        return False
+    low = path.replace("\\", "/").lower()
+    # Must look like a browser, not generic "snap"
+    if "chromium" in low or "chrome" in low:
+        return True
+    return False
+
+
+def _normalize_browser_path(path: str | None) -> str | None:
+    """Return a usable browser executable path.
+
+    Critical: /snap/bin/chromium often realpath()'s to /usr/bin/snap.
+    Using /usr/bin/snap as browser_path makes DrissionPage fail to connect.
+    Keep the original /snap/bin/chromium wrapper path instead.
+    """
+    if not path:
+        return None
+    path = str(path).strip()
+    if not path:
+        return None
+    if not (os.path.isfile(path) or os.path.islink(path) or os.path.exists(path)):
+        return None
+
+    # Prefer original path if already valid (esp. /snap/bin/chromium)
+    if _looks_like_browser_path(path):
+        # If under /snap/bin/, never realpath — that collapses to /usr/bin/snap
+        if path.startswith("/snap/bin/"):
+            return path
+        try:
+            real = os.path.realpath(path)
+        except Exception:
+            real = path
+        if _looks_like_browser_path(real):
+            return real
+        # realpath bad (e.g. snap) but original ok
+        return path
+
+    # realpath might still help for normal symlinks
+    try:
+        real = os.path.realpath(path)
+    except Exception:
+        real = ""
+    if real and _looks_like_browser_path(real):
+        return real
+    return None
 
 
 def _first_existing_browser(candidates) -> str | None:
     for cand in candidates:
-        if cand and (os.path.isfile(cand) or os.path.islink(cand)):
-            return cand
+        if not cand:
+            continue
+        norm = _normalize_browser_path(cand)
+        if norm:
+            return norm
     return None
 
 
@@ -835,19 +914,29 @@ def resolve_browser_path():
 
     Priority:
       1. config browser_path (absolute)
-      2. env BROWSER_PATH / CHROME_PATH
+      2. env BROWSER_PATH / CHROME_PATH / CHROMIUM_PATH
       3. browser_prefer=chromium|chrome|auto
          auto → Chromium first when turnstilePatch exists (needed for CF)
       4. any remaining candidate
+
+    Never returns /usr/bin/snap (common snap symlink collapse bug).
     """
     # Optional override from config.json "browser_path"
     override = str((config.get("browser_path") if isinstance(config, dict) else "") or "").strip()
-    if override and (os.path.isfile(override) or os.path.islink(override)):
-        return override
-    for env_key in ("BROWSER_PATH", "CHROME_PATH", "CHROMIUM_PATH"):
+    if override:
+        norm = _normalize_browser_path(override)
+        if norm:
+            return norm
+        print(f"  [browser] ignore invalid browser_path={override!r}", flush=True)
+
+    for env_key in ("BROWSER_PATH", "CHROMIUM_PATH", "CHROME_PATH"):
         env_path = (os.environ.get(env_key) or "").strip()
-        if env_path and (os.path.isfile(env_path) or os.path.islink(env_path)):
-            return env_path
+        if not env_path:
+            continue
+        norm = _normalize_browser_path(env_path)
+        if norm:
+            return norm
+        print(f"  [browser] ignore invalid {env_key}={env_path!r}", flush=True)
 
     prefer = str((config.get("browser_prefer") if isinstance(config, dict) else "") or "auto").strip().lower()
     if prefer in ("", "default", "detect"):
@@ -869,8 +958,7 @@ def resolve_browser_path():
         else:
             order = list(CHROME_CANDIDATES) + list(CHROMIUM_CANDIDATES)
 
-    path = _first_existing_browser(order)
-    return path
+    return _first_existing_browser(order)
 
 
 def apply_stealth_patches(page=None, log_callback=None) -> bool: