Building coldstart: what broke, what held up

This is the long version. If you want the short pitch for coldstart — what it is and why it exists — read the main post first. This one is for people who want to see the iteration story: the design decisions that didn't work, the ones that did, and why. The arc is roughly: I started with a simple idea, hit real codebases, and watched it break in interesting ways. Each section below is a thing that broke and what I did about it. The starting point: one folder-path domain per file The first versio