Initial build: stash server + browser extension

Server (Express + better-sqlite3 + FTS5, mirroring keep's stack):
/api/capture (upsert-on-url, per PROPOSAL.md's dedup decision),
/api/articles (list/search/mark-read/delete), plus a minimal
server-rendered reading list and reader view at / and /read/:id
(token passed as ?t= there since browser navigation can't set an
Authorization header). Bearer-token auth generated via `npm run
token` — no login flow, matching keep's one-time identity
registration pattern.

Extension (Manifest V3, sideloaded, no store distribution): toolbar
click or context menu "Send to stash" runs @mozilla/readability
(vendored into extension/lib/) against the current page, falling back
to raw rendered HTML when extraction comes back too thin. Options
page for one-time server URL + token entry.

Verified end-to-end with the real extension loaded in a live Chromium
instance (not just unit-tested extraction logic): capture against a
real page, dedup-on-recapture, mark-read, FTS5 search, 401 on missing
auth, and both server-rendered views all confirmed working.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/server/index.ts

@@ -0,0 +1,19 @@
+import express from 'express';
+import cors from 'cors';
+import routes from './routes.js';
+import ui from './ui.js';
+
+const app = express();
+const PORT = Number(process.env.PORT) || 3070;
+
+app.use(express.json({ limit: '5mb' })); // article HTML can be sizeable
+app.use(cors()); // the extension calls this from arbitrary page origins
+
+app.use('/api', routes);
+app.use('/', ui);
+
+app.get('/api/health', (_req, res) => res.json({ ok: true }));
+
+app.listen(PORT, () => {
+  console.log(`stash server listening on :${PORT}`);
+});