feat(pwa): logicsrc credentials app — real auth + Turso, redesigned; retire commandboard-api credshare

Adds apps/pwa: an Express + libSQL/Turso app that is now the home of team
credential sharing, with the moshcode-style auth stack ported and reskinned to
match logicsrc.com (light theme, Inter, green accent).

apps/pwa
- auth: email/password (scrypt), passkeys (WebAuthn), CoinPay OAuth, cookie
  sessions, and lsk_ API keys for the CLI via a loopback OAuth-PKCE flow
  (/cli/authorize + /cli/token). Ported from the moshcode PWA.
- credshare API (/api/credshare/*): teams, members, invites, vaults, sealed
  grants, ciphertext secrets, audit — authed by session OR Bearer lsk_ key.
  Zero-knowledge: only ciphertext + sealed vault keys + public keys stored.
- teams dashboard, accept-invite, and settings (API keys) pages, server-rendered
  in the LogicSRC brand (lib/html.mjs).
- migrations (libSQL) 001_auth + 002_credshare, migrate-on-boot; Turso via
  TURSO_DATABASE_URL / TURSO_AUTH_TOKEN, or a local file db for dev.
- trimmed moshcode-specific approvals/credits/push/deliver.

CLI
- `logicsrc login` now does browser loopback OAuth-PKCE against the app and
  stores an lsk_ token (email-OTP removed); --token for CI. Client repointed.

Distribution
- install.sh (served at logicsrc.com/install.sh) installs the CLI from the
  GitHub repo: tarball -> npm install -> `npm run build:cli` -> logicsrc wrapper.
- root build:cli builds only the CLI's workspace chain (skips web/api/next).

Cleanup
- removed the commandboard-api credshare backend (superseded by the PWA) and its
  Supabase/Turso stores + libsql dep; commandboard-api tests green (40).
- removed the Next.js /teams page (the PWA is the web UI now).

Verified end-to-end: two accounts register on the PWA, mint lsk_ keys, CLI login
uploads identity keys, owner pushes an encrypted .env, teammate invited ->
accepted -> granted -> pulls the exact file. Server stores ciphertext only.
Full workspace build + tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/pwa/public/passkey.js

@@ -0,0 +1,53 @@
+/* Passkey button: try to sign in with a discoverable passkey; if there's none,
+   register a new one. Uses the @simplewebauthn/browser UMD bundle (/vendor). */
+(function () {
+  var btn = document.getElementById("passkey-btn");
+  var msg = document.getElementById("passkey-msg");
+  if (!btn) return;
+
+  function csrf() {
+    var m = document.cookie.match(/(?:^|; )mc_csrf=([^;]+)/);
+    return m ? decodeURIComponent(m[1]) : "";
+  }
+  function post(url, body) {
+    return fetch(url, {
+      method: "POST",
+      headers: { "content-type": "application/json", "x-csrf-token": csrf() },
+      body: JSON.stringify(body || {}),
+    });
+  }
+  function say(t) { if (msg) msg.textContent = t; }
+
+  async function register() {
+    say("creating a passkey…");
+    var opts = await (await post("/auth/passkey/register/options")).json();
+    var att = await SimpleWebAuthnBrowser.startRegistration({ optionsJSON: opts });
+    var r = await post("/auth/passkey/register/verify", att);
+    var out = await r.json();
+    if (out.ok) location.href = out.redirect || "/";
+    else say(out.error || "couldn't create passkey");
+  }
+
+  async function login() {
+    var opts = await (await post("/auth/passkey/login/options")).json();
+    var asr = await SimpleWebAuthnBrowser.startAuthentication({ optionsJSON: opts });
+    var r = await post("/auth/passkey/login/verify", asr);
+    var out = await r.json();
+    if (out.ok) { location.href = out.redirect || "/"; return true; }
+    throw new Error(out.error || "sign-in failed");
+  }
+
+  btn.addEventListener("click", async function () {
+    if (!window.PublicKeyCredential) { say("this device doesn't support passkeys"); return; }
+    btn.disabled = true;
+    try {
+      await login();
+    } catch (e) {
+      // no discoverable credential / user cancelled login → offer to register
+      try { await register(); }
+      catch (e2) { say(String(e2.message || e2)); }
+    } finally {
+      btn.disabled = false;
+    }
+  });
+})();