feat: add email worker using Cloudflare Email Sending API

[decofe]

Adds a new apps/email Cloudflare Worker for sending transactional emails using the Cloudflare Email Sending API (SEND_EMAIL binding).

Changes

• apps/email/src/index.ts — Hono worker with POST /send endpoint, validates request body with Zod against the SendEmail.send() builder signature
• apps/email/wrangler.json — Worker config with send_email binding
• AGENTS.md — Added email app to existing apps table

Usage

curl -X POST https://<worker-url>/send \
  -H 'Content-Type: application/json' \
  -d '{
    "from": {"email": "noreply@tempo.xyz", "name": "Tempo"},
    "to": ["user@example.com"],
    "subject": "Hello from Tempo",
    "text": "Hello World!",
    "html": "<h1>Hello World!</h1>"
  }'

Testing

cd apps/email && pnpm check  # biome + types pass

Prompted by: georgios

[github-actions]

Bundle Size Report

Metric	Size	Δ Change
Total	4.2 MB	-606.3 KB (-12.4%)
Gzip	1.2 MB	-101.0 KB (-7.6%)
Brotli	1.0 MB	-80.7 KB (-7.0%)

Chunk changes (>1KB)

Chunk	Change
assets/KeyManager.js (removed)	-477.4 KB
assets/QueryBuilder.js (removed)	-423.4 KB
assets/router.js	-298.3 KB
assets/wagmi.config.js	-283.2 KB
assets/_hash.js	-128.1 KB
assets/BaseTanStackRouterDevtoolsPanel-Bmws3ikM.js (removed)	-99.5 KB
assets/Intro.js (removed)	-66.0 KB
assets/createSsrRpc.js (removed)	-43.8 KB
assets/isAddressEqual.js	-33.5 KB
assets/Hash.js (removed)	-31.0 KB
assets/path.js (removed)	-30.6 KB
assets/FloatingTanStackRouterDevtools-B7vy70jP.js (removed)	-24.4 KB
assets/_layout.js	-22.2 KB
assets/stringify.js (removed)	-19.7 KB
assets/address.js	-14.1 KB
assets/Address.js	-13.1 KB
assets/getAction.js	-13.0 KB
assets/base.js (removed)	-12.8 KB
assets/utils.js	-10.1 KB
assets/token.server.js (removed)	-9.8 KB
...and 41 more

Compared against main branch (baseline from 2/4/2026, 5:13:51 PM)

[github-actions]

Cloudflare Deployments

App	Environment	Status	Preview
explorer	devnet	[OK] Deployed	View Preview
explorer	mainnet	[OK] Deployed	View Preview
explorer	testnet	[OK] Deployed	View Preview
fee-payer	devnet	[OK] Deployed	View Preview
fee-payer	moderato	[OK] Deployed	View Preview
fee-payer	privy	[OK] Deployed	View Preview
og	-	[OK] Deployed	View Preview
perf	-	[OK] Deployed	View Preview
tokenlist	-	[OK] Deployed	View Preview