Package for public GitHub release

Add open-source scaffolding and CI; remove Claude-specific dev notes from the
published tree.

- Remove CLAUDE.md from tracking (kept locally, now git-ignored).
- CHANGELOG.md (Keep a Changelog; v1.0 → v1.1.1).
- SECURITY.md (private vuln reporting + operator guidance).
- CONTRIBUTING.md (dev setup, conventions, PR flow).
- .github/: bug + feature issue templates, PR template.
- .github/workflows/ci.yml: byte-compile, validate example config, docker build.
- .github/workflows/release.yml: on a version tag, publish a multi-arch
  (amd64 + arm64) image to GHCR.
- README: license/release/CI badges, prebuilt-image (GHCR) run instructions,
  and a corrected Python-version note (3.9–3.11; netifaces caveat).

Badges and image names use an `OWNER` placeholder to replace with the GitHub
namespace after the repo is created.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  python:
+    name: Python checks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+      - name: Byte-compile server
+        run: python -m compileall -q server.py
+      - name: Validate example config is valid JSON
+        run: python -c "import json; json.load(open('config.json.example'))"
+
+  docker:
+    name: Docker build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build image
+        run: docker build -t ads-bit:ci .

.github/workflows/release.yml

@@ -0,0 +1,52 @@
+name: Release
+
+# Build and publish a multi-arch image to GitHub Container Registry (GHCR)
+# whenever a version tag is pushed (e.g. v1.1.2). Lets users run a prebuilt
+# image — including on Raspberry Pi (arm64) — without building locally.
+
+on:
+  push:
+    tags: ["v*"]
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  image:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Compute lowercase image name
+        id: img
+        run: echo "name=ghcr.io/${GITHUB_REPOSITORY,,}" >> "$GITHUB_OUTPUT"
+
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Docker metadata (tags & labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ steps.img.outputs.name }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=raw,value=latest
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}