feat: phase 0 foundation — monorepo scaffold, backend, frontend, CI, docker

Establishes the skeleton every later phase builds on: Go+Gin API with
zap logging, /api/healthz, SQLite+goose runner; Vite+React18+TS strict+
Tailwind v4 frontend with bento-mono theme tokens; openapi.yaml driving
a generated TS client; oxlint with vendored anti-slop rules; GitHub CI;
multi-stage Dockerfile -> 33.6MB distroless image; docker compose up
serves the blank board.


Generated with [Devin](https://devin.ai)

Authored By: TDvorak <[email protected]>
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: ci
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  backend:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: apps/backend
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: apps/backend/go.mod
+          cache-dependency-path: apps/backend/go.sum
+      - run: go build ./...
+      - run: go vet ./...
+      - run: go test ./...
+
+  frontend:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+      - run: npm ci
+      - run: npm run typecheck
+      - run: npm run lint
+      - run: npm run build