Initial commit with server startup infrastructure

Core infrastructure:
- Uber fx dependency injection
- Chi router with middleware stack
- SQLite database with embedded migrations
- Embedded templates and static assets
- Structured logging with slog

Features implemented:
- Authentication (login, logout, session management, argon2id hashing)
- App management (create, edit, delete, list)
- Deployment pipeline (clone, build, deploy, health check)
- Webhook processing for Gitea
- Notifications (ntfy, Slack)
- Environment variables, labels, volumes per app
- SSH key generation for deploy keys

Server startup:
- Server.Run() starts HTTP server on configured port
- Server.Shutdown() for graceful shutdown
- SetupRoutes() wires all handlers with chi router

Dockerfile

@@ -0,0 +1,39 @@
+# Build stage
+FROM golang:1.23-alpine AS builder
+
+RUN apk add --no-cache git make gcc musl-dev
+
+# Install golangci-lint
+RUN go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+RUN go install golang.org/x/tools/cmd/goimports@latest
+
+WORKDIR /src
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+# Run all checks - build fails if any check fails
+RUN make check
+
+# Build the binary
+RUN make build
+
+# Runtime stage
+FROM alpine:3.19
+
+RUN apk add --no-cache ca-certificates tzdata git openssh-client docker-cli
+
+WORKDIR /app
+
+COPY --from=builder /src/bin/upaasd /app/upaasd
+
+# Create data directory
+RUN mkdir -p /data
+
+ENV UPAAS_DATA_DIR=/data
+ENV UPAAS_PORT=8080
+
+EXPOSE 8080
+
+ENTRYPOINT ["/app/upaasd"]