Wi-Fi QR code generator

Encodes your network name, password and security type in the `WIFI:` format that iOS and Android both read natively. Scanning it offers to join the network — no app and no typing.

The format has escaping rules that catch people out. Semicolons, commas, colons and backslashes inside an SSID or password must be backslash-escaped, or the parser stops at the first one and the code half-works — which is far more confusing than failing outright. That escaping is handled here. Two practical notes: the SSID is case-sensitive and must match exactly, including spaces, and a hidden network needs the hidden flag set or the phone will not find it after decoding. For a café or an office, printing the code and taping it up is genuinely the least friction way to share a long password.