Use Node 22+ native --env-file=../../.env in dev/spike scripts so
packages pick up root .env variables without a dotenv dependency.
Also add devenv, direnv, and pre-commit entries to .gitignore.

Documents architecture, dev setup, lexicon conventions, AT Protocol
patterns, TypeScript/Hono gotchas, and git conventions.

Mark lexicon definitions and project scaffolding as complete, with
result notes. Spike script is written but awaiting PDS credentials.

Set up Turborepo monorepo with pnpm workspaces and devenv for the atBB
decentralized forum project. Defines 5 new AT Proto lexicon schemas
(category, role, membership, reaction, modAction) alongside the 3
existing ones, with a YAML→JSON→TypeScript build pipeline. Scaffolds
the Hono AppView API server, HTMX web UI server, and PDS spike script.