#1: implement F0 foundation - monorepo, migrations, Go domain layer, service skeletons, CI

Stands up the LambdaMail monorepo per PLAN.md's F0 milestone: local dev
scaffolding (.env.example, Makefile, .gitignore excluding PLAN.md/docs/
.superpowers/), the full initial Postgres schema as a golang-migrate
migration, the complete Go domain layer for services/protocols (value
objects, entities, domain events - zero external imports beyond
github.com/google/uuid) with unit tests, health-checked service skeletons
for auth/storage (TypeScript) and webmail (Next.js), a local
docker-compose.yaml wiring all services together, a language-enforcement
lint script, and a GitHub Actions CI workflow.

Built via 11 sequential tasks under subagent-driven development, each with
an independent implementer + reviewer cycle. Fixes applied during review:
DomainName.IsPunycode() added to satisfy the promised interface; ioredis
default-import typing under NodeNext; next.js bumped 15.0.3->15.5.21 to
resolve high/critical CVEs; lang-lint.mjs corrected to not flag its own
banned-terms list; web service healthcheck added so compose --wait
actually waits on it; webmail Dockerfile's missing public/ directory:
protocols go.mod version aligned with CI's Go 1.22 pin.

Known follow-ups for later phases (not blocking F0): go-arch-lint isn't
wired into CI yet; live docker compose up and migration apply have not
been exercised in this dev environment (no Docker/psql available here)
and will get their first real run in CI, which does have Docker.

.github/workflows/ci.yml

@@ -0,0 +1,73 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  lang-lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: node scripts/lang-lint.mjs
+
+  go-protocols:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: services/protocols
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version: "1.22" }
+      - run: go vet ./...
+      - run: go test ./... -v
+
+  ts-auth:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: services/auth
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with: { node-version: "20" }
+      - run: npm install
+      - run: npm run lint
+      - run: npm test
+
+  ts-storage:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: services/storage
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with: { node-version: "20" }
+      - run: npm install
+      - run: npm run lint
+      - run: npm test
+
+  webmail-build:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: services/webmail
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with: { node-version: "20" }
+      - run: npm install
+      - run: npm run build
+
+  compose-up:
+    runs-on: ubuntu-latest
+    needs: [go-protocols, ts-auth, ts-storage, webmail-build]
+    steps:
+      - uses: actions/checkout@v4
+      - run: cp .env.example .env
+      - run: docker compose --env-file .env up --build --wait
+      - run: docker compose ps
+      - run: docker compose down -v