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>

tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "ES2023",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "outDir": "dist",
+    "rootDir": "src",
+    "strict": true,
+    "esModuleInterop": true
+  },
+  "include": ["src"]
+}