feat(packaging): put the bundled meshbay-node on the per-user PATH

The installer had no console entry point, so running the CLI meant cd-ing
into resources\node-runtime\ every time. installer.nsh now adds that dir to
HKCU\Environment\Path on install and removes it on uninstall, via stock
WordFunc.nsh (electron-builder's NSIS bundle has no EnVar plugin). It points
at the real meshbay-node.exe dir — not a shim — so `where meshbay-node`,
findNodeBinary and the W3 autostart launcher all resolve to the same binary.
A WM_SETTINGCHANGE broadcast nudges open shells; new ones just work.

Rebuilt: electron-builder --win nsis compiles the WordFunc includes fine,
MeshBay-Setup-0.1.0.exe (155 MB). test_packaging_win.py covers the add/remove
symmetry.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

2 files changed, 55 insertions, 5 deletions

diff --git a/packages/meshbay-client/build/installer.nsh b/packages/meshbay-client/build/installer.nsh
index cf8e5ff..15a840f 100644
--- a/packages/meshbay-client/build/installer.nsh
+++ b/packages/meshbay-client/build/installer.nsh
@@ -1,22 +1,50 @@
 ; electron-builder NSIS customisation (auto-included: build/installer.nsh).
 ;
-; Per-user install, no elevation (package.json build.nsis). These macros only
-; deal with the one piece of state that lives outside the install directory:
-; the W3 "run at sign-in" launcher the node's own CLI can create.
+; Per-user install, no elevation (package.json build.nsis). This does two things
+; beyond the default: put the bundled daemon on the user's PATH so `meshbay-node`
+; works in a terminal, and clean up the one piece of state that lives outside
+; the install directory (the W3 "run at sign-in" launcher).
 ;
-; Deliberately NOT touched here:
+; Deliberately NOT touched:
 ;   - %LOCALAPPDATA%\meshbay\  (node.toml, keystore.enc, unlock.key, data/) --
 ;     the keystore must survive an uninstall/reinstall; installers place files,
 ;     never remove secrets.
 
+!include "WinMessages.nsh"
+!include "WordFunc.nsh"
+!insertmacro WordAdd
+!insertmacro un.WordAdd
+
+; The dir electron-builder drops resources into. `meshbay-node.exe` and its
+; frozen Python live directly in here. A fixed suffix of $INSTDIR, so both the
+; add (install) and the remove (uninstall, where $INSTDIR is still known) match
+; the exact same string.
+!define MB_NODE_BIN "$INSTDIR\resources\node-runtime"
+
 !macro customInstall
-  ; resources\node-runtime\meshbay-node.exe is overwritten by this install; a
+  ; resources\node-runtime\meshbay-node.exe is about to be overwritten; a
   ; daemon still running from a previous version holds the file open.
   nsExec::Exec 'taskkill /IM meshbay-node.exe /F'
+
+  ; Add the daemon dir to the per-user PATH (HKCU\Environment). WordAdd is a
+  ; stock NSIS macro over a ';'-delimited list -- it is a no-op if the entry is
+  ; already there, so a reinstall does not double it. New shells only; the
+  ; broadcast tells already-open Explorer/shells to reload the environment.
+  ReadRegStr $0 HKCU "Environment" "Path"
+  ${WordAdd} "$0" ";" "+${MB_NODE_BIN}" $1
+  WriteRegExpandStr HKCU "Environment" "Path" "$1"
+  SendMessage ${HWND_BROADCAST} ${WM_WININICHANGE} 0 "STR:Environment" /TIMEOUT=5000
 !macroend
 
 !macro customUnInstall
   nsExec::Exec 'taskkill /IM meshbay-node.exe /F'
+
+  ; Take our entry back out of PATH, leaving the rest of it alone.
+  ReadRegStr $0 HKCU "Environment" "Path"
+  ${un.WordAdd} "$0" ";" "-${MB_NODE_BIN}" $1
+  WriteRegExpandStr HKCU "Environment" "Path" "$1"
+  SendMessage ${HWND_BROADCAST} ${WM_WININICHANGE} 0 "STR:Environment" /TIMEOUT=5000
+
   ; meshbay_node.platform._startup_vbs() -- if the user ran "meshbay-node
   ; autostart install" (or toggled it in the client), this points wscript at
   ; the binary we are about to delete, and would error at every sign-in.
diff --git a/packages/meshbay-node/tests/test_packaging_win.py b/packages/meshbay-node/tests/test_packaging_win.py
index 1b7521a..8c8e272 100644
--- a/packages/meshbay-node/tests/test_packaging_win.py
+++ b/packages/meshbay-node/tests/test_packaging_win.py
@@ -151,3 +151,25 @@ def test_customInstall_stops_a_running_daemon_before_overwriting_it():
     nsh = NSH.read_text(encoding="utf-8")
     body = nsh.split("!macro customInstall", 1)[1].split("!macroend", 1)[0]
     assert "taskkill /IM meshbay-node.exe /F" in body
+
+
+def test_the_bundled_daemon_goes_on_the_user_path_and_comes_back_off():
+    """
+    The installer has no console entry point of its own; without this the
+    operator has to `cd` into resources\\node-runtime\\ to run `meshbay-node`.
+    The add uses stock WordFunc (no EnVar plugin — electron-builder's NSIS does
+    not bundle it) and the same $INSTDIR-relative string on the way out.
+    """
+    nsh = NSH.read_text(encoding="utf-8")
+    assert "!insertmacro WordAdd" in nsh and "!insertmacro un.WordAdd" in nsh
+
+    install = nsh.split("!macro customInstall", 1)[1].split("!macroend", 1)[0]
+    uninstall = nsh.split("!macro customUnInstall", 1)[1].split("!macroend", 1)[0]
+    assert 'HKCU "Environment" "Path"' in install
+    assert "${WordAdd}" in install and '"+${MB_NODE_BIN}"' in install
+    assert "${un.WordAdd}" in uninstall and '"-${MB_NODE_BIN}"' in uninstall
+    # New shells need the broadcast to notice.
+    assert "WM_WININICHANGE" in install and "WM_WININICHANGE" in uninstall
+    # PATH points at the real .exe dir, so `where meshbay-node` resolves to the
+    # binary the client and the W3 launcher use too — not a shim.
+    assert 'MB_NODE_BIN "$INSTDIR\\resources\\node-runtime"' in nsh