docs: correct HQ run instructions — launch server from repo root

The DB path resolves to ./data/hq.db against the process working directory, so
the server must run from the repo root; `cd apps/hq && npm start` would look in
apps/hq/data and boot an empty database. Found while red-teaming the split by
booting the server live against the real data/hq.db.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -60,10 +60,14 @@ runbook (server, HTTPS, backups, Gmail/AWS/import wiring, the Postgres switch) i
 ```bash
 npm install                     # from the repo root (workspaces: packages/*, apps/*)
 
-# Backend — HQ server (builds the server bundle, then runs it on :5182)
-cd apps/hq && npm start
-# First boot creates data/hq.db and prints a one-time owner password — capture it.
-# Log in as admin@tecnostac.com with that password, then change it.
+# Backend — HQ server. Build the bundle, then run it FROM THE REPO ROOT: the DB
+# path resolves to ./data/hq.db against the current working directory, so the
+# server must be launched from the repo root (not from apps/hq, which would look
+# in apps/hq/data and boot an empty database).
+npm run build --workspace @sims/hq
+node apps/hq/dist/server.cjs     # serves :5182 (API, built web UI, /share/:token)
+# First boot on an empty data/ creates data/hq.db and prints a one-time owner
+# password — capture it. Log in as admin@tecnostac.com, then change it.
 
 # Frontend — hq-web dev server (Vite on :5183, proxies /api and /share to :5182)
 cd apps/hq-web && npm run dev