nginx Access Log Parser

Paste nginx access log lines, one per line. Three layouts are supported: the built-in `combined` format, the Common Log Format subset of it, and `combined` followed by a quoted X-Forwarded-For field. Auto mode recognizes only the two layouts nginx itself ships — `combined` and the Common Log Format subset — and only when the field count matches exactly and the bracketed and quoted fields line up. It will not name the `combined` + X-Forwarded-For layout, because a tenth quoted field is indistinguishable from any other custom variable: `$http_x_forwarded_for` is a request header that may hold arbitrary text, while `$server_addr` or a custom variable may well hold an address, so the value settles nothing. A line auto mode cannot place is reported as an unrecognized layout, and a custom log_format stays visible as a custom log_format. Choosing a format yourself is your own claim about the line, and it is respected as written: `combined + X-Forwarded-For` reads the tenth field as X-Forwarded-For whatever it contains, and any other format reads its known fields from the start of the line and lists surplus tokens exactly as written instead of giving them a name. A `-` placeholder is reported as an absent value, not as the literal text. The status code is shown as logged and the reason phrase is not invented; use the HTTP status reference for that. Input is capped at 400,000 characters and 2,000 lines. Everything runs locally; nothing is uploaded, stored, or written into the URL.