diff --git a/CHANGELOG.md b/CHANGELOG.md
index c67c76d4..e55c97c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # aicodeman
 
+## 0.9.1
+
+### Patch Changes
+
+- Multi-monitor & settings UX fixes.
+  - **Multi-monitor button (remote servers):** the "span displays" button spawns `scripts/span-codeman.sh` server-side, so on a non-macOS Codeman server it can't open a window on your machine. The non-macOS API error now explains this and points to running the script locally on your Mac with the remote server URL; the script header documents the same remote-client workflow.
+  - **App Settings modal:** stop the modal overflowing horizontally on narrow viewports.
+  - **systemd:** sync the `codeman-web.service` template with the deployed unit.
+
 ## 0.9.0
 
 ### Minor Changes
diff --git a/CLAUDE.md b/CLAUDE.md
index d68a5268..018c9c13 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -56,7 +56,7 @@ When user says "COM":
 
 CI runs `npm run check:lockfile` on every push/PR, so lockfile drift fails the build even if the `version-packages` script is bypassed.
 
-**Version**: 0.9.0 (must match `package.json`)
+**Version**: 0.9.1 (must match `package.json`)
 
 ## Project Overview
 
diff --git a/package-lock.json b/package-lock.json
index 1a318614..057b5c3b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "aicodeman",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "aicodeman",
-      "version": "0.9.0",
+      "version": "0.9.1",
       "hasInstallScript": true,
       "license": "MIT",
       "workspaces": [
diff --git a/package.json b/package.json
index 2f163391..ce895b35 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "aicodeman",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "description": "The missing control plane for AI coding agents - run 20 autonomous agents with real-time monitoring and session persistence",
   "type": "module",
   "main": "dist/index.js",
diff --git a/scripts/span-codeman.sh b/scripts/span-codeman.sh
index 06c98275..daf9fb45 100755
--- a/scripts/span-codeman.sh
+++ b/scripts/span-codeman.sh
@@ -16,6 +16,18 @@
 # per-display and will NOT span. We size a windowed app to the union of all
 # displays instead. macOS only.
 #
+# ── REMOTE CLIENT (Codeman server on another machine) ────────────────────────
+# The header "multi-monitor" button spawns this script SERVER-SIDE, so it opens
+# the window on the SERVER's displays and is gated to a macOS server. If your
+# Codeman runs elsewhere (e.g. a headless Linux box reached over Tailscale) and
+# YOUR monitors are on a Mac, the button can't help — the server can't open a
+# window on your machine. Instead, run this script LOCALLY on the Mac and pass
+# the remote URL as the argument:
+#   ./span-codeman.sh "https://your-codeman.example.ts.net"
+# The osascript/browser launch all happen on the Mac; only the page is served
+# remotely, so the spanning window lands on your monitors. The "separate Spaces"
+# prerequisite above still applies on the Mac.
+#
 set -euo pipefail
 
 URL="${1:-http://localhost:5000}"
diff --git a/src/web/routes/system-routes.ts b/src/web/routes/system-routes.ts
index d202fbd4..2c72f63e 100644
--- a/src/web/routes/system-routes.ts
+++ b/src/web/routes/system-routes.ts
@@ -268,7 +268,13 @@ export function registerSystemRoutes(
     if (process.platform !== 'darwin') {
       return reply
         .code(400)
-        .send(createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Multi-monitor spanning is only supported on macOS.'));
+        .send(
+          createErrorResponse(
+            ApiErrorCode.INVALID_INPUT,
+            'Multi-monitor spanning runs on the Codeman server, which is not macOS. ' +
+              'If your monitors are on a remote Mac, run scripts/span-codeman.sh locally on that Mac with this server URL — see the script header for details.'
+          )
+        );
     }
     // Resolve the bundled launcher relative to this module (works from src/ and dist/).
     const scriptPath = join(dirname(fileURLToPath(import.meta.url)), '../../../scripts/span-codeman.sh');