Devlog 1 - Getting started

My first devlog! DevBox just went from an empty folder to something I can
actually use, with three working tools.

The idea: one page with all the little tools devs keep googling - JSON, Base64,
URL encoding - running right in your browser. No submit buttons, works offline,
nothing you type ever leaves your machine.

I started with the shell, so adding a tool is dead easy: one folder plus one
line in a config file gets it into the sidebar, routing, and search. Then the
first three tools - JSON Formatter, Base64, and URL, the last two auto-detecting
whether to encode or decode.

The tricky part was that auto-detect: it only treats input as Base64 if it
survives a clean round-trip, otherwise plain text turns to garbage.

Next up: four more tools (Regex, Timestamp, Color, Text Case).