feat(build): add remote-build-display-control.sh for workstation → Mac builds

Copies display_control.m to laptop 01 via SSH, compiles universal binary
(x86_64 + arm64) on the remote Mac, pulls binary back to resources/bin/.
Defaults to 192.168.32.101; accepts optional IP override as $1.

README: restructure display_control build section — Option A (remote from
workstation, preferred) and Option B (direct on Mac).

README.md

@@ -354,32 +354,53 @@ See `documentation/PROJECT__AE_Events_Launcher_Native_integration.md` Section 8
 
 ### One-Time: Build the `display_control` Binary (macOS)
 
-The `display_control` binary provides native CoreGraphics display mirror/extend without any Homebrew dependency. It must be compiled once on a Mac and committed to the repo so it is bundled into every packaged app.
+The `display_control` binary provides native CoreGraphics display mirror/extend without any Homebrew dependency. It must be compiled on a Mac (Xcode CLT required) and committed to the repo so it is bundled into every packaged app. Produces a universal binary (x86_64 + arm64) that runs on both Intel and Apple Silicon Macs.
+
+Rebuild only if `scripts/display_control.m` changes.
+
+#### Option A — From the Linux workstation (preferred)
+
+Laptop 01 (`192.168.32.101`) is the designated build Mac — Xcode CLT is installed there.
+The remote build script copies the source over SSH, compiles on that Mac, and pulls the binary back.
 
 ```bash
-# Requires Xcode Command Line Tools (one-time install):
+# From the repo root on the workstation:
-xcode-select --install
+./scripts/remote-build-display-control.sh
 
-# From the repo root:
+# Override the build Mac IP if needed:
+./scripts/remote-build-display-control.sh 192.168.32.102
+```
+
+The script prints `file resources/bin/display_control` at the end. Confirm both arches appear:
+```
+resources/bin/display_control: Mach-O universal binary with 2 architectures: [x86_64] [arm64]
+```
+
+Then commit:
+```bash
+git add resources/bin/display_control
+git commit -m "build: update display_control binary (universal)"
+```
+
+#### Option B — Directly on a Mac
+
+If you have repo access on the Mac itself (Xcode CLT required — `xcode-select --install`):
+
+```bash
 ./scripts/build-display-control.sh
-
+# Expected last output line: x86_64 arm64
-# The script compiles x86_64 and arm64 separately then links a universal binary.
-# Expected output at the end: x86_64 arm64
 
 # Test with a second display connected:
 ./resources/bin/display_control status
 ./resources/bin/display_control extend
 ./resources/bin/display_control mirror
 
-# Commit the binary:
 git add resources/bin/display_control
-git commit -m "build: add display_control binary (macOS CoreGraphics)"
+git commit -m "build: update display_control binary (universal)"
 ```
 
 Once committed, `brew install displayplacer` is no longer required on any venue Mac. The `displayplacer` fallback remains in the handler only for `configStr` per-device overrides.
 
-Rebuild only if `scripts/display_control.m` changes.
-
 ---
 
 ### Build Requirements (System Dependencies)

scripts/remote-build-display-control.sh

@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+# scripts/remote-build-display-control.sh
+# Build the display_control universal binary on a remote Mac via SSH,
+# then pull the result back to resources/bin/display_control.
+#
+# Use this from the Linux workstation when you don't have a Mac locally.
+# The target Mac must have Xcode Command Line Tools installed.
+#
+# USAGE:
+#   ./scripts/remote-build-display-control.sh              # uses default Mac (laptop 01)
+#   ./scripts/remote-build-display-control.sh 192.168.32.102
+#
+# The default IP is laptop 01 — the designated build Mac.
+# Change DEFAULT_IP below if Xcode moves to a different laptop.
+#
+# SSH key must already be installed on the target:
+#   ssh-copy-id "speaker ready"@192.168.32.101
+
+set -eo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+SRC="$SCRIPT_DIR/display_control.m"
+OUT_BIN="$REPO_ROOT/resources/bin/display_control"
+
+SSH_USER="speaker ready"
+DEFAULT_IP="192.168.32.101"
+IP="${1:-$DEFAULT_IP}"
+
+REMOTE_TMP="/tmp/ae_display_control_build"
+
+echo "═══════════════════════════════════════════════"
+echo "  Remote build: display_control"
+echo "  Build Mac: $SSH_USER @ $IP"
+echo "═══════════════════════════════════════════════"
+
+# ── Step 1: Copy source to remote ────────────────────────────────────────────
+
+echo ""
+echo "Step 1/4 — Copying source to $IP..."
+ssh "$SSH_USER@$IP" "mkdir -p $REMOTE_TMP"
+scp "$SRC" "$SSH_USER@$IP:$REMOTE_TMP/display_control.m"
+
+# ── Step 2: Build universal binary on remote ──────────────────────────────────
+
+echo ""
+echo "Step 2/4 — Building on $IP..."
+ssh "$SSH_USER@$IP" bash << 'ENDSSH'
+set -e
+REMOTE_TMP="/tmp/ae_display_control_build"
+SRC="$REMOTE_TMP/display_control.m"
+TMP_X86="$REMOTE_TMP/display_control_x86_64"
+TMP_ARM="$REMOTE_TMP/display_control_arm64"
+OUT="$REMOTE_TMP/display_control"
+
+echo "  Compiling x86_64..."
+clang -arch x86_64 -framework Cocoa -framework Carbon -o "$TMP_X86" "$SRC"
+
+echo "  Compiling arm64..."
+clang -arch arm64 -framework Cocoa -framework Carbon -o "$TMP_ARM" "$SRC"
+
+echo "  Linking universal binary..."
+lipo -create -output "$OUT" "$TMP_X86" "$TMP_ARM"
+rm "$TMP_X86" "$TMP_ARM"
+chmod +x "$OUT"
+
+echo "  Archs: $(lipo -archs "$OUT")"
+ENDSSH
+
+# ── Step 3: Pull binary back ──────────────────────────────────────────────────
+
+echo ""
+echo "Step 3/4 — Pulling binary to resources/bin/..."
+mkdir -p "$(dirname "$OUT_BIN")"
+scp "$SSH_USER@$IP:$REMOTE_TMP/display_control" "$OUT_BIN"
+chmod +x "$OUT_BIN"
+
+# ── Step 4: Clean up remote ───────────────────────────────────────────────────
+
+echo ""
+echo "Step 4/4 — Cleaning up remote..."
+ssh "$SSH_USER@$IP" "rm -rf $REMOTE_TMP"
+
+# ── Done ──────────────────────────────────────────────────────────────────────
+
+echo ""
+echo "═══════════════════════════════════════════════"
+echo "  Built: $OUT_BIN"
+file "$OUT_BIN"
+echo ""
+echo "  If both archs shown above, you're good:"
+echo "    git add resources/bin/display_control"
+echo "    git commit -m \"build: update display_control binary (universal)\""
+echo "═══════════════════════════════════════════════"