feat: OTA updates for start-tunnel via apt repository (untested)

- Add apt repo publish script (build/apt/publish-deb.sh) for S3-hosted repo
- Add apt source config and GPG key placeholder (apt/)
- Add tunnel.update.check and tunnel.update.apply RPC endpoints
- Wire up update API in tunnel frontend (api service + mock)
- Uses systemd-run --scope to survive service restart during update

build/apt/publish-deb.sh

@@ -0,0 +1,130 @@
+#!/bin/bash
+#
+# Publish .deb files to an S3-hosted apt repository.
+#
+# Usage: publish-deb.sh <deb-file-or-directory> [<deb-file-or-directory> ...]
+#
+# Environment variables:
+#   GPG_PRIVATE_KEY  - Armored GPG private key (imported if set)
+#   GPG_KEY_ID       - GPG key ID for signing
+#   S3_ACCESS_KEY    - S3 access key
+#   S3_SECRET_KEY    - S3 secret key
+#   S3_ENDPOINT      - S3 endpoint (default: https://nyc3.digitaloceanspaces.com)
+#   S3_BUCKET        - S3 bucket name (default: start9-debs)
+#   SUITE            - Apt suite name (default: stable)
+#   COMPONENT        - Apt component name (default: main)
+
+set -e
+
+if [ $# -eq 0 ]; then
+    echo "Usage: $0 <deb-file-or-directory> [...]" >&2
+    exit 1
+fi
+
+BUCKET="${S3_BUCKET:-start9-debs}"
+ENDPOINT="${S3_ENDPOINT:-https://nyc3.digitaloceanspaces.com}"
+SUITE="${SUITE:-stable}"
+COMPONENT="${COMPONENT:-main}"
+REPO_DIR="$(mktemp -d)"
+
+cleanup() {
+    rm -rf "$REPO_DIR"
+}
+trap cleanup EXIT
+
+# Import GPG key if provided
+if [ -n "$GPG_PRIVATE_KEY" ]; then
+    echo "$GPG_PRIVATE_KEY" | gpg --batch --import 2>/dev/null
+fi
+
+# Configure s3cmd
+S3CMD_CONFIG="$(mktemp)"
+cat > "$S3CMD_CONFIG" <<EOF
+[default]
+access_key = ${S3_ACCESS_KEY}
+secret_key = ${S3_SECRET_KEY}
+host_base = $(echo "$ENDPOINT" | sed 's|https://||')
+host_bucket = %(bucket)s.$(echo "$ENDPOINT" | sed 's|https://||')
+use_https = True
+EOF
+
+s3() {
+    s3cmd -c "$S3CMD_CONFIG" "$@"
+}
+
+# Sync existing repo from S3
+echo "Syncing existing repo from s3://${BUCKET}/ ..."
+s3 sync --no-mime-magic "s3://${BUCKET}/" "$REPO_DIR/" 2>/dev/null || true
+
+# Collect all .deb files from arguments
+DEB_FILES=()
+for arg in "$@"; do
+    if [ -d "$arg" ]; then
+        while IFS= read -r -d '' f; do
+            DEB_FILES+=("$f")
+        done < <(find "$arg" -name '*.deb' -print0)
+    elif [ -f "$arg" ]; then
+        DEB_FILES+=("$arg")
+    else
+        echo "Warning: $arg is not a file or directory, skipping" >&2
+    fi
+done
+
+if [ ${#DEB_FILES[@]} -eq 0 ]; then
+    echo "No .deb files found" >&2
+    exit 1
+fi
+
+# Copy each deb to the pool
+for deb in "${DEB_FILES[@]}"; do
+    PKG_NAME="$(dpkg-deb --field "$deb" Package)"
+    POOL_DIR="$REPO_DIR/pool/${COMPONENT}/${PKG_NAME:0:1}/${PKG_NAME}"
+    mkdir -p "$POOL_DIR"
+    cp "$deb" "$POOL_DIR/"
+    echo "Added: $(basename "$deb") -> pool/${COMPONENT}/${PKG_NAME:0:1}/${PKG_NAME}/"
+done
+
+# Generate Packages indices for each architecture
+for arch in amd64 arm64 riscv64; do
+    BINARY_DIR="$REPO_DIR/dists/${SUITE}/${COMPONENT}/binary-${arch}"
+    mkdir -p "$BINARY_DIR"
+    (
+        cd "$REPO_DIR"
+        dpkg-scanpackages --arch "$arch" pool/ > "$BINARY_DIR/Packages"
+        gzip -k -f "$BINARY_DIR/Packages"
+    )
+    echo "Generated Packages index for ${arch}"
+done
+
+# Generate Release file
+(
+    cd "$REPO_DIR/dists/${SUITE}"
+    apt-ftparchive release \
+        -o "APT::FTPArchive::Release::Origin=Start9" \
+        -o "APT::FTPArchive::Release::Label=Start9" \
+        -o "APT::FTPArchive::Release::Suite=${SUITE}" \
+        -o "APT::FTPArchive::Release::Codename=${SUITE}" \
+        -o "APT::FTPArchive::Release::Architectures=amd64 arm64 riscv64" \
+        -o "APT::FTPArchive::Release::Components=${COMPONENT}" \
+        . > Release
+)
+echo "Generated Release file"
+
+# Sign if GPG key is available
+if [ -n "$GPG_KEY_ID" ]; then
+    (
+        cd "$REPO_DIR/dists/${SUITE}"
+        gpg --default-key "$GPG_KEY_ID" --batch --yes --detach-sign -o Release.gpg Release
+        gpg --default-key "$GPG_KEY_ID" --batch --yes --clearsign -o InRelease Release
+    )
+    echo "Signed Release file with key ${GPG_KEY_ID}"
+else
+    echo "Warning: GPG_KEY_ID not set, Release file is unsigned" >&2
+fi
+
+# Upload to S3
+echo "Uploading to s3://${BUCKET}/ ..."
+s3 sync --acl-public --no-mime-magic "$REPO_DIR/" "s3://${BUCKET}/"
+
+rm -f "$S3CMD_CONFIG"
+echo "Done."