add: Docker image and compose for containerized deploy

Multi-stage build (cgo for the SQLite logger) on debian-slim with ffmpeg,
opus-tools, and ca-certificates bundled. Compose mounts ./data/config.yaml
and ./data/media; SIGTERM cancels in-flight encodes cleanly.

Dockerfile

@@ -0,0 +1,17 @@
+# Build needs cgo (the logger uses github.com/mattn/go-sqlite3), so no scratch/static image.
+FROM golang:1.26-bookworm AS build
+WORKDIR /src
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=1 go build -ldflags="-s -w" -o /videnc-vibe ./cmd/videnc/
+
+FROM debian:bookworm-slim
+# ffmpeg gives ffmpeg+ffprobe; opus-tools gives opusenc; ca-certificates for OMDb/TVmaze HTTPS.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      ffmpeg opus-tools ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+COPY --from=build /videnc-vibe /usr/local/bin/videnc-vibe
+# logs.db + log files land in the working dir — make it the mounted /data so they persist.
+WORKDIR /data
+ENTRYPOINT ["videnc-vibe", "-c", "/config/config.yaml"]