feat: add server_log_path() for in-app MCP log viewer (#6)

bcc_core.py

@@ -474,7 +474,7 @@ def _normalize_unicode(text: str, notes: list[str]) -> str:
     out = text
     for junk in _JUNK_CHARS:
         out = out.replace(junk, "")
-    out = out.replace(" ", " ")  # non-breaking space
+    out = out.replace(" ", " ")  # non-breaking space
     for smart, ascii_q in _QUOTE_MAP.items():
         out = out.replace(smart, ascii_q)
     if out != text:
@@ -1270,6 +1270,25 @@ def diagnostics_text(name: str, data: dict) -> str:
     return "\n".join(L)
 
 
+def server_log_path(name: str) -> Path | None:
+    """
+    The platform-specific Claude Desktop MCP server log file for `name`, or
+    None if it doesn't exist yet (nothing has been logged for this server).
+
+    macOS  : ~/Library/Logs/Claude/mcp-server-<name>.log   (one file per server)
+    Windows: %APPDATA%\\Claude\\logs\\mcp.log               (one shared file)
+    Other platforms: Claude Desktop doesn't ship a log in a known location -> None.
+    """
+    if sys.platform == "darwin":
+        p = Path.home() / "Library" / "Logs" / "Claude" / f"mcp-server-{name}.log"
+    elif sys.platform.startswith("win"):
+        appdata = Path(os.environ.get("APPDATA", Path.home() / "AppData" / "Roaming"))
+        p = appdata / "Claude" / "logs" / "mcp.log"
+    else:
+        return None
+    return p if p.is_file() else None
+
+
 _STDERR_CAP = 4096  # bytes