Add sign-in to the app

Install and wire @convex-dev/auth for the current app: a provider (passkeys by default, or OAuth/password), the server config, the client hooks, and a sign-in UI — correctly, including the auth.config.ts that's the #1 real-world auth footgun.

Steps

Install @convex-dev/auth (pinned build) and add it to convex.config.ts. With pnpm, also pnpm add jose (it won't hoist otherwise); you need it for step 3.
Add the provider in convex/auth.ts (Passkey by default; Password or OAuth like Google on request).
Generate the auth keys HEADLESSLY. Do NOT run the interactive npx @convex-dev/auth wizard: it needs a login/TTY and hangs in non-interactive, anonymous, or CI runs (the #1 auth time-sink). Generate JWT_PRIVATE_KEY + JWKS deterministically with jose: node -e 'import("jose").then(async({generateKeyPair,exportPKCS8,exportJWK})=>{const k=await generateKeyPair("RS256",{extractable:true});const priv=await exportPKCS8(k.privateKey);const pub=await exportJWK(k.publicKey);process.stdout.write(JSON.stringify({JWT_PRIVATE_KEY:priv.trimEnd().replace(/\n/g," "),JWKS:JSON.stringify({keys:[{use:"sig",...pub}]})}))})' > .auth-keys.json Then set JWT_PRIVATE_KEY and JWKS (from .auth-keys.json) plus SITE_URL on the deployment. Prefer the Convex MCP envSet tool, one call per var, to avoid shell-quoting the multi-line key. CLI fallback: use the NAME=VALUE form (npx convex env set "JWT_PRIVATE_KEY=$JWT"), NEVER env set JWT_PRIVATE_KEY "$JWT" (the value starts with -----BEGIN and the CLI parses the leading - as an unknown flag). SITE_URL is the dev URL (e.g. http://localhost:3000). Delete .auth-keys.json after.
Write convex/auth.config.ts (the silently-always-signed-out bug lives here if it's wrong).
Wire the client: ConvexAuthProvider, the sign-in component, and route guards. If you import shadcn/ui primitives (button, input, textarea, label, and so on), add them first with npx shadcn@latest add <name>; a missing @/components/ui/* is a hard build error.
Verify a sign-in round-trips before declaring done.