diff --git a/.github/workflows/install-e2e.yml b/.github/workflows/install-e2e.yml
index 6320a848dc..8ca7875642 100644
--- a/.github/workflows/install-e2e.yml
+++ b/.github/workflows/install-e2e.yml
@@ -47,11 +47,11 @@ on:
   workflow_dispatch:
     inputs:
       route:
-        description: 'Which combinations to run. all = every OS; both/update/installer = the linux legs; windows-desktop = the windows legs.'
+        description: 'Which combinations to run. all = every OS; both/update/installer = the linux legs; windows-desktop = the windows legs; macos-desktop = the macos legs.'
         required: false
         type: choice
         default: all
-        options: [all, both, update, installer, windows-desktop]
+        options: [all, both, update, installer, windows-desktop, macos-desktop]
       tag-count:
         description: 'How many release tags to sample (newest, oldest, and a spread between).'
         required: false
@@ -179,7 +179,7 @@ jobs:
 
   macos:
     name: ${{ matrix.name }}
-    if: github.event_name != 'workflow_dispatch' || inputs.route == 'all'
+    if: github.event_name != 'workflow_dispatch' || contains(fromJSON('["all", "macos-desktop"]'), inputs.route)
     needs: generate-matrix
     strategy:
       fail-fast: false
diff --git a/tests/install/e2e-assets/drive-dmg-install.sh b/tests/install/e2e-assets/drive-dmg-install.sh
new file mode 100644
index 0000000000..60ddd1e35f
--- /dev/null
+++ b/tests/install/e2e-assets/drive-dmg-install.sh
@@ -0,0 +1,147 @@
+#!/usr/bin/env bash
+# Drive the Hermes-Setup dmg bootstrap through its first-run GUI.
+#
+# The Setup app is Tauri (Rust + system webview), so Playwright/Electron
+# attach never works. Launch the binary bare in the background (it inherits
+# the redirect env), click "Install Hermes ->" with native input, then watch
+# the install land on disk: checkout + venv console script.
+#
+# Usage:
+#   drive-dmg-install.sh --app-bin <path> --install-dir <path> \
+#     [--install-timeout-secs 2700] [--proof-dir <dir>]
+#
+# Exit 0: install landed. Non-zero: click never registered or the install
+# never landed; desktop screenshots in --proof-dir say which.
+set -euo pipefail
+
+APP_BIN=""
+INSTALL_DIR=""
+INSTALL_TIMEOUT_SECS=2700
+PROOF_DIR="."
+while [ "$#" -gt 0 ]; do
+  case "$1" in
+    --app-bin) APP_BIN="$2"; shift 2 ;;
+    --install-dir) INSTALL_DIR="$2"; shift 2 ;;
+    --install-timeout-secs) INSTALL_TIMEOUT_SECS="$2"; shift 2 ;;
+    --proof-dir) PROOF_DIR="$2"; shift 2 ;;
+    *) echo "error: unknown argument: $1" >&2; exit 1 ;;
+  esac
+done
+[ -n "$APP_BIN" ] && [ -n "$INSTALL_DIR" ] || { echo 'error: --app-bin and --install-dir are required' >&2; exit 1; }
+mkdir -p "$PROOF_DIR"
+
+log() { echo "[drive-dmg-install] $*"; }
+shot() {
+  # screencapture works regardless of app internals; -x mutes the shutter.
+  screencapture -x "$PROOF_DIR/$1.png" 2>/dev/null || true
+  log "screenshot: $PROOF_DIR/$1.png"
+}
+
+"$APP_BIN" &
+SETUP_PID=$!
+log "launched $APP_BIN (pid $SETUP_PID)"
+cleanup() { kill "$SETUP_PID" 2>/dev/null || true; }
+trap cleanup EXIT
+
+# Wait for the installer window, then click the install button. The webview's
+# button is not a native control and System Events is not permitted assistive
+# access on the runners (error -25208), so post real CGEvents with cliclick.
+# The AppleScript half only READS window geometry (position/size need no
+# assistive grant). Re-click every probe until the install starts: a click
+# that lands before the webview finishes painting is swallowed, and
+# re-clicking a started install hits a progress screen (harmless).
+command -v cliclick >/dev/null 2>&1 || brew install --quiet cliclick
+
+window_geometry() {
+  osascript <<'OSA' 2>/dev/null
+tell application "System Events"
+  set procs to (every process whose name contains "Hermes")
+  if (count of procs) = 0 then return "no-process"
+  set p to item 1 of procs
+  if (count of windows of p) = 0 then return "no-window"
+  set w to window 1 of p
+  set {x, y} to position of w
+  set {wd, ht} to size of w
+  return (x as text) & " " & (y as text) & " " & (wd as text) & " " & (ht as text)
+end tell
+OSA
+}
+
+click_install() {
+  local geo
+  geo="$(window_geometry)"
+  case "$geo" in
+    no-process|no-window|'') echo "$geo"; return 0 ;;
+  esac
+  # shellcheck disable=SC2086
+  set -- $geo
+  local x=$1 y=$2 wd=$3 ht=$4
+  # Button center sits at ~65% of window height (measured from the
+  # installer's first-run screen at its fixed 880x620 window size).
+  local cx=$((x + wd / 2))
+  local cy=$((y + ht * 65 / 100))
+  cliclick "c:${cx},${cy}" 2>&1 || true
+  echo "clicked ${cx},${cy} (window ${x},${y} ${wd}x${ht})"
+}
+
+HERMES_BIN="$INSTALL_DIR/venv/bin/hermes"
+# The bootstrap runs 11 stages; checkout + venv land in the first few and
+# the desktop app build is near the end, so success requires all three or
+# the EXIT trap kills the installer mid-build.
+installed_app() {
+  local cand
+  for cand in \
+    "$INSTALL_DIR/apps/desktop/release/mac-arm64/Hermes.app" \
+    "$INSTALL_DIR/apps/desktop/release/mac/Hermes.app" \
+    "/Applications/Hermes.app"; do
+    [ -d "$cand" ] && return 0
+  done
+  return 1
+}
+install_complete() {
+  [ -d "$INSTALL_DIR/.git" ] && [ -x "$HERMES_BIN" ] && installed_app
+}
+DEADLINE=$((SECONDS + INSTALL_TIMEOUT_SECS))
+FIRST_SHOT=0
+CLICKS=0
+while :; do
+  if install_complete; then
+    log "install landed: checkout + venv console script + Hermes.app present"
+    shot "02-install-landed"
+    break
+  fi
+  if ! kill -0 "$SETUP_PID" 2>/dev/null; then
+    # The bootstrap relaunches the desktop and exits on success; only fail
+    # if it died without the install landing (give the FS one last look).
+    sleep 5
+    install_complete && continue
+    shot "ERROR-setup-exited"
+    log "Hermes-Setup exited (pid $SETUP_PID) before the install landed"
+    exit 1
+  fi
+  if [ "$FIRST_SHOT" -eq 0 ] && [ "$SECONDS" -gt 10 ]; then
+    shot "00-setup-window"
+    FIRST_SHOT=1
+  fi
+  # Keep clicking until the install shows up on disk; count for the log.
+  result="$(click_install || true)"
+  CLICKS=$((CLICKS + 1))
+  [ $((CLICKS % 6)) -eq 1 ] && log "click attempt $CLICKS: $result"
+  if [ "$CLICKS" -eq 3 ]; then shot "01-after-first-clicks"; fi
+  if [ "$SECONDS" -ge "$DEADLINE" ]; then
+    shot "ERROR-install-timeout"
+    log "install did not land within ${INSTALL_TIMEOUT_SECS}s ($CLICKS clicks attempted)"
+    exit 1
+  fi
+  sleep 10
+done
+
+# Success: the bootstrap owns its own exit (it relaunches the desktop).
+# Leave it a grace window, then stop it if it lingers; the caller's asserts
+# take over from here.
+for _ in 1 2 3 4 5 6; do
+  kill -0 "$SETUP_PID" 2>/dev/null || break
+  sleep 5
+done
+log "done"
+exit 0
diff --git a/tests/install/macos-desktop-e2e.sh b/tests/install/macos-desktop-e2e.sh
index ccf36a4f93..c623431d35 100755
--- a/tests/install/macos-desktop-e2e.sh
+++ b/tests/install/macos-desktop-e2e.sh
@@ -226,12 +226,17 @@ phase_install() {
   app_bin="$(find "$app/Contents/MacOS" -type f -perm +111 | head -1)"
   [ -n "$app_bin" ] || fail "no executable inside $app/Contents/MacOS"
 
-  # Run the installer binary DIRECTLY: `open` launches via launchd, which
-  # inherits NONE of the redirect env (GIT_CONFIG_GLOBAL, HOME) - the whole
-  # isolation would silently evaporate. Direct exec is the same binary and
-  # the same first-launch flow.
+  # The Setup app is Tauri (Rust + system webview): Playwright/Electron
+  # attach never works, and run bare it waits forever on its setup-choice
+  # screen. Launch it in the background with our env (direct exec, not
+  # `open`: launchd inherits NONE of the redirect env) and drive the
+  # "Install Hermes" button with native input.
   local rc=0
-  "$app_bin" 2>&1 | ts_prefix > "$LOG_DIR/bootstrap-install.log" || rc=$?
+  bash "$ASSETS/drive-dmg-install.sh" \
+    --app-bin "$app_bin" \
+    --install-dir "$INSTALL_DIR" \
+    --proof-dir "$LOG_DIR" 2>&1 \
+    | ts_prefix > "$LOG_DIR/bootstrap-install.log" || rc=$?
   log_group "Hermes-Setup (dmg bootstrap) transcript" "$LOG_DIR/bootstrap-install.log"
   hdiutil detach "$mount" >/dev/null 2>&1 || true
   [ "$rc" -eq 0 ] || fail "dmg bootstrap exited $rc; transcript above"
@@ -249,15 +254,23 @@ phase_install() {
   ok "installed app: $(find_installed_app)"
 }
 
-run_playwright_update() {
-  # $1: spec file to launch from. Installs the driver's OWN pinned
-  # @playwright/test into a scratch dir (never the installed tree's copy).
-  local spec="$1"
+ensure_playwright() {
+  # Install the driver's OWN pinned @playwright/test into a scratch dir
+  # (never the installed tree's copy). Idempotent across phases.
   local pw_dir="$WORK_ROOT/playwright"
+  [ -d "$pw_dir/node_modules/@playwright/test" ] && { printf '%s' "$pw_dir"; return 0; }
   mkdir -p "$pw_dir"
   (cd "$pw_dir" && npm install --no-save --no-audit --no-fund \
     "@playwright/test@$PLAYWRIGHT_VERSION" 2>&1 | ts_prefix > "$LOG_DIR/playwright-install.log") \
     || { log_group "playwright install transcript" "$LOG_DIR/playwright-install.log"; fail "playwright install failed"; }
+  printf '%s' "$pw_dir"
+}
+
+run_playwright_update() {
+  # $1: spec file to launch from.
+  local spec="$1"
+  local pw_dir
+  pw_dir="$(ensure_playwright)"
   cp "$ASSETS/launch-from-spec.mjs" "$pw_dir/"
   local rc=0
   (cd "$pw_dir" && node launch-from-spec.mjs \