Add Homebrew Cask for macOS .app bundle

Adds a cask template and updates update-tap.sh to also push
Casks/attn.rb to the tap, so users can install the native .app
via `brew install --cask lightsofapollo/attn/attn`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: lightsofapollo

homebrew/attn-cask.rb.template

@@ -0,0 +1,14 @@
+cask "attn" do
+  version "%%VERSION%%"
+  sha256 "%%SHA256_DARWIN_ARM64_APP%%"
+
+  url "https://github.com/lightsofapollo/attn/releases/download/v#{version}/attn-v#{version}-darwin-arm64.app.zip"
+  name "attn"
+  desc "A beautiful markdown viewer that launches from the CLI"
+  homepage "https://github.com/lightsofapollo/attn"
+
+  app "attn.app"
+  binary "#{appdir}/attn.app/Contents/MacOS/attn"
+
+  zap trash: "~/.attn"
+end

homebrew/update-tap.sh

@@ -17,17 +17,23 @@ VERSION="${1:?Usage: update-tap.sh <version>}"
 TAG="v${VERSION}"
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-TEMPLATE="${SCRIPT_DIR}/attn.rb.template"
+FORMULA_TEMPLATE="${SCRIPT_DIR}/attn.rb.template"
+CASK_TEMPLATE="${SCRIPT_DIR}/attn-cask.rb.template"
 
-if [ ! -f "$TEMPLATE" ]; then
-  echo "Template not found: ${TEMPLATE}" >&2
+if [ ! -f "$FORMULA_TEMPLATE" ]; then
+  echo "Formula template not found: ${FORMULA_TEMPLATE}" >&2
+  exit 1
+fi
+if [ ! -f "$CASK_TEMPLATE" ]; then
+  echo "Cask template not found: ${CASK_TEMPLATE}" >&2
   exit 1
 fi
 
 echo "Fetching SHA256 checksums for ${TAG}..."
 
 SHA_DARWIN_ARM64="$(curl -sfL "https://github.com/${REPO}/releases/download/${TAG}/attn-${TAG}-darwin-arm64.sha256" | awk '{print $1}')"
 SHA_LINUX_X64="$(curl -sfL "https://github.com/${REPO}/releases/download/${TAG}/attn-${TAG}-linux-x64.sha256" | awk '{print $1}')"
+SHA_DARWIN_ARM64_APP="$(curl -sfL "https://github.com/${REPO}/releases/download/${TAG}/attn-${TAG}-darwin-arm64.app.zip.sha256" | awk '{print $1}')"
 
 if [ -z "$SHA_DARWIN_ARM64" ]; then
   echo "Failed to fetch darwin-arm64 SHA256" >&2
@@ -37,23 +43,28 @@ if [ -z "$SHA_LINUX_X64" ]; then
   echo "Failed to fetch linux-x64 SHA256" >&2
   exit 1
 fi
+if [ -z "$SHA_DARWIN_ARM64_APP" ]; then
+  echo "Failed to fetch darwin-arm64 .app.zip SHA256" >&2
+  exit 1
+fi
+
+echo "  darwin-arm64:     ${SHA_DARWIN_ARM64}"
+echo "  linux-x64:        ${SHA_LINUX_X64}"
+echo "  darwin-arm64 app: ${SHA_DARWIN_ARM64_APP}"
 
-echo "  darwin-arm64: ${SHA_DARWIN_ARM64}"
-echo "  linux-x64:    ${SHA_LINUX_X64}"
+# --- Update Formula ---
 
-# Generate formula from template
 FORMULA="$(sed \
   -e "s/%%VERSION%%/${VERSION}/g" \
   -e "s/%%SHA256_DARWIN_ARM64%%/${SHA_DARWIN_ARM64}/g" \
   -e "s/%%SHA256_LINUX_X64%%/${SHA_LINUX_X64}/g" \
-  "$TEMPLATE")"
+  "$FORMULA_TEMPLATE")"
 
-# Get the current file SHA from the tap repo (needed for the GitHub API update)
 CURRENT_SHA="$(gh api "repos/${TAP_REPO}/contents/Formula/attn.rb" --jq '.sha' 2>/dev/null || true)"
 
 ARGS=(
   --method PUT
-  --field "message=Update attn to ${VERSION}"
+  --field "message=Update attn formula to ${VERSION}"
   --field "content=$(echo "$FORMULA" | base64)"
   --field "branch=main"
 )
@@ -65,3 +76,27 @@ fi
 gh api "repos/${TAP_REPO}/contents/Formula/attn.rb" "${ARGS[@]}"
 
 echo "Formula updated in ${TAP_REPO}"
+
+# --- Update Cask ---
+
+CASK="$(sed \
+  -e "s/%%VERSION%%/${VERSION}/g" \
+  -e "s/%%SHA256_DARWIN_ARM64_APP%%/${SHA_DARWIN_ARM64_APP}/g" \
+  "$CASK_TEMPLATE")"
+
+CASK_CURRENT_SHA="$(gh api "repos/${TAP_REPO}/contents/Casks/attn.rb" --jq '.sha' 2>/dev/null || true)"
+
+CASK_ARGS=(
+  --method PUT
+  --field "message=Update attn cask to ${VERSION}"
+  --field "content=$(echo "$CASK" | base64)"
+  --field "branch=main"
+)
+
+if [ -n "$CASK_CURRENT_SHA" ]; then
+  CASK_ARGS+=(--field "sha=${CASK_CURRENT_SHA}")
+fi
+
+gh api "repos/${TAP_REPO}/contents/Casks/attn.rb" "${CASK_ARGS[@]}"
+
+echo "Cask updated in ${TAP_REPO}"