Add MIT license, CONTRIBUTING, and SECURITY docs for open-sourcing

Preparing to open the project up beyond this repo's own use:
- LICENSE: MIT, and a "license": "MIT" field on the root and all three
  workspace package.json files.
- CONTRIBUTING.md: dev workflow, the mock-relay testing setup (most
  sandboxes/CI have no route to public Nostr relays, and registration
  needs a 2-of-N ack quorum so a single mock relay always fails), the
  spec-first process for anything touching wire format or crypto
  (docs/spec.md is canonical; speculative ideas go in their own doc, not
  the spec), and stricter expectations for crypto/key-handling changes.
- SECURITY.md: private vulnerability disclosure via GitHub's advisory
  flow rather than public issues, given this handles private keys and
  password-derived secrets client-side; states current audit status
  plainly (none yet).
- README: short "Contributing" section pointing at all three.

Co-Authored-By: Claude <[email protected]>
Claude-Session: https://claude.ai/code/session_01GWJbXXhvTx9wo59jSz57J6

CONTRIBUTING.md

@@ -0,0 +1,106 @@
+# Contributing to BitLogin
+
+Thanks for taking a look. BitLogin is a small monorepo — read this before your
+first PR, it'll save you a round trip.
+
+## Layout
+
+See `README.md` for the full package breakdown. In short: `packages/core` is
+the framework-free protocol implementation (crypto, capsules, Nostr relay
+I/O, account flows), `packages/widget` is the `<bitlogin-auth>` custom
+element and its crypto Web Worker, and `packages/demo` is the static site
+that consumes both.
+
+## Getting started
+
+```bash
+npm install
+npm test           # runs @bitlogin/core's vitest suite
+npm run typecheck  # tsc -b for core, tsc --noEmit for widget
+npm run build      # builds core, then widget
+```
+
+If you edit `packages/core` and a downstream typecheck seems stale (TS
+happily reports success against old `.d.ts` output), delete the incremental
+build cache and rebuild:
+
+```bash
+rm -f packages/core/tsconfig.tsbuildinfo packages/widget/tsconfig.tsbuildinfo
+npm run build -w @bitlogin/core && npm run typecheck -w @bitlogin/widget
+```
+
+## Testing without a real Nostr relay
+
+Most sandboxes (and CI) have no route to public Nostr relays. Protocol-level
+tests instead run against an in-memory mock relay,
+`packages/core/src/test-support/mockRelay.ts` — a minimal WebSocket server
+implementing enough of NIP-01 (EVENT/REQ/CLOSE/OK, addressable/replaceable
+replacement semantics) for real round trips: register → publish → login from
+a "clean device," phrase recovery, password rotation, relay-loss → replica
+repair, and so on. New account-flow tests should follow the existing pattern
+in `packages/core/src/account/account.e2e.test.ts` — spin up 2-3 `MockRelay`
+instances in `beforeEach`, close them in `afterEach` (registration/login
+require a 2-of-N acknowledgement quorum by default, so a single mock relay
+will fail every write).
+
+For widget/UI changes, there's no equivalent automated browser suite yet —
+verify manually against the built widget in a real browser (Chromium is
+fine) pointed at a locally started `MockRelay` instance via the
+`vault-relays`/`discovery-relays` attributes, since real relays aren't
+reachable from most contributor sandboxes either.
+
+## The spec is canonical
+
+`docs/spec.md` (currently v0.3) is the source of truth for the protocol
+itself — wire formats, KDF parameters, capsule structure, derivation paths,
+threat model. Code comments reference it by section (`§11.2`, `§17.4`, …).
+
+If a change affects anything the spec describes — a new capsule field, a
+derivation change, a new recovery path — update `docs/spec.md` in the same
+PR, not after the fact. Purely additive widget/UI features that don't touch
+wire format or crypto (a new screen, a UX fix) don't need a spec change.
+Speculative/future ideas that aren't decided yet belong in a separate doc
+(see `docs/second-factor.md` and `docs/future-recovery-options.md` for the
+pattern: proposal + pros/cons, explicitly marked as not implemented) rather
+than in the spec itself.
+
+## Working on cryptography or key handling
+
+This code touches private keys and password-derived secrets, so changes
+here get held to a higher bar than typical UI work:
+
+- Prefer the audited libraries already in use (`@noble/curves`,
+  `@noble/hashes`, `@noble/ciphers`, `@scure/bip39`, native WebCrypto,
+  `hash-wasm`) over adding a new dependency or hand-rolled primitive.
+- Private keys and passwords must never be logged, persisted in plaintext,
+  or held in memory longer than the operation needs (`§11.10`). In the
+  widget, they must never leave the crypto Web Worker — the main thread
+  only ever sees public keys, signed events, and ciphertext.
+- If you're changing KDF parameters, encryption modes, or derivation paths,
+  explain why in the PR description, not just what — these are exactly the
+  kind of change that's cheap to review now and expensive to unwind once
+  real accounts depend on it.
+- Add or update test vectors (`packages/core/src/crypto/crypto.test.ts`) for
+  any primitive-level change.
+
+## Reporting a security vulnerability
+
+Don't open a public issue for a suspected vulnerability in the crypto,
+capsule handling, or key custody — see `SECURITY.md` for the private
+disclosure process.
+
+## Style
+
+- TypeScript strict mode; `packages/core` stays framework- and DOM-free so
+  it can run in Node, a browser, or a worker.
+- Comments explain *why*, not *what* — skip a comment if the code's already
+  clear without it.
+- Match the existing code's structure rather than introducing a new
+  abstraction for something only used once.
+
+## Pull requests
+
+- Run `npm test` and `npm run typecheck` before opening a PR; both must
+  pass.
+- Keep the description focused on *why*, not a restatement of the diff.
+- Small, focused PRs review faster than one that bundles unrelated changes.

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 PR0M3TH3AN
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to
+deal in the Software without restriction, including without limitation the
+rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

README.md

@@ -142,3 +142,10 @@ HKDF, ScalarExpand, AES-256-GCM, JCS, fixed padding buckets).
 - Passphrases are generated from the EFF long Diceware wordlist
   (`diceware-wordlist-en-eff`), matching the spec's ~12.9-bits/word,
   six-word/~77-bit default (§9.2).
+
+## Contributing
+
+MIT licensed — see `LICENSE`. See `CONTRIBUTING.md` for the dev workflow,
+mock-relay testing (no route to public relays in most sandboxes/CI), and
+the spec-first process for anything touching wire format or crypto. Found
+a security issue? See `SECURITY.md` rather than opening a public issue.

SECURITY.md

@@ -0,0 +1,39 @@
+# Security Policy
+
+BitLogin handles private keys and password-derived secrets client-side —
+security issues here can mean account takeover, not just a bug.
+
+## Reporting a vulnerability
+
+Please do not open a public GitHub issue for a suspected vulnerability.
+
+Instead, use GitHub's private reporting flow: go to this repo's **Security**
+tab → **Report a vulnerability**. This opens a private advisory visible only
+to maintainers until a fix is ready, so details aren't public before users
+can update.
+
+Include, if you can:
+- What's affected (crypto primitive, capsule format, key handling, a
+  specific derivation) and why it's exploitable.
+- A minimal reproduction or proof of concept.
+- Anything you already tried in `docs/spec.md`'s threat model that this
+  falls outside of.
+
+## Scope
+
+In scope: anything in `packages/core` (crypto, capsule construction/parsing,
+Nostr relay I/O, account flows) and `packages/widget` (the crypto Web
+Worker, the `window.nostr` provider, key custody boundaries between the
+worker and the main thread).
+
+Out of scope: the demo site's own UI/branding bugs that don't touch account
+security — file those as normal public issues instead.
+
+## Status
+
+This project has not yet had an independent third-party security audit —
+see the README's "What's implemented" section for the current verification
+status (protocol-level test suite plus manual real-browser verification).
+Treat that as part of the threat model when reporting: we'd rather hear
+about a real issue than have it wait for a formal audit that hasn't happened
+yet.

package.json

@@ -2,6 +2,7 @@
   "name": "bitlogin-monorepo",
   "version": "0.1.0",
   "private": true,
+  "license": "MIT",
   "description": "BitLogin — static, relay-backed portable Nostr account protocol and embeddable login widget",
   "workspaces": [
     "packages/core",

packages/core/package.json

@@ -2,6 +2,7 @@
   "name": "@bitlogin/core",
   "version": "0.1.0",
   "private": true,
+  "license": "MIT",
   "type": "module",
   "description": "BitLogin protocol core: crypto, capsules, Nostr relay I/O, account flows. Framework- and DOM-free.",
   "main": "./dist/index.js",

packages/demo/package.json

@@ -2,6 +2,7 @@
   "name": "@bitlogin/demo",
   "version": "0.1.0",
   "private": true,
+  "license": "MIT",
   "type": "module",
   "description": "BitLogin marketing/landing site, integration docs, and account manager — a plain static site consuming @bitlogin/widget via a <script> tag.",
   "scripts": {

packages/widget/package.json

@@ -2,6 +2,7 @@
   "name": "@bitlogin/widget",
   "version": "0.1.0",
   "private": true,
+  "license": "MIT",
   "type": "module",
   "description": "BitLogin embeddable login widget: a <bitlogin-auth> custom element plus a window.nostr NIP-07-compatible provider, backed by a dedicated crypto Web Worker.",
   "main": "./dist/bitlogin.js",