Add Technical Kiwi website with Go, templ, and HTMX.

Single-page site with gallery by album and event, contact form over SMTP,
Docker dev/prod setup, and on-server image derivatives. Gallery photos stay
local (app/images/ is gitignored).

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -0,0 +1,29 @@
+ARG GO_VERSION=1.25
+FROM golang:${GO_VERSION}-bookworm AS builder
+
+RUN go install github.com/a-h/templ/cmd/templ@latest
+
+WORKDIR /build
+COPY app/go.mod app/go.sum ./
+RUN go mod download
+
+COPY app/ ./
+RUN templ generate && CGO_ENABLED=0 go build -ldflags="-s -w" -o /server ./cmd/server
+
+FROM debian:bookworm-slim
+
+RUN apt-get update \
+	&& apt-get install -y --no-install-recommends ca-certificates \
+	&& rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=builder /server ./server
+COPY app/static ./static
+COPY app/images ./images
+RUN ./server -thumbs
+
+EXPOSE 8080
+ENV ADDR=:8080
+
+CMD ["./server"]