fix(windows): open companion window on click + prevent UI freeze

- Click "Open Water" now calls requestShowWindow() via TCP instead of
  opening water.95ent.ai in the system browser. Falls back to
  watermorph:// protocol if companion is not running.
- Companion handles SHOW_WINDOW command by calling win.show()/focus().
- Reduced connect timeout 3000ms → 200ms + 5s retry throttle to prevent
  the message thread from freezing when companion is not running.
- Fixed titleBarStyle on Windows: use hiddenInset + titleBarOverlay
  (branded mauve #8B5CF6) instead of 'hidden' which breaks on Windows.

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

Author: grauxmusic

CompanionWin/main.js

@@ -29,13 +29,22 @@ let dawState = { bpm: 0, key: '', isConnected: false }
 // ── Window ───────────────────────────────────────────────────────────────────
 
 function createWindow() {
+  // titleBarStyle 'hidden' doesn't work correctly on Windows (content area
+  // doesn't fill under the title bar). Use titleBarOverlay for Windows
+  // custom chrome, which keeps a native draggable area but lets us color it.
+  const isMac = process.platform === 'darwin'
   win = new BrowserWindow({
     width:           420,
     height:          700,
     minWidth:        340,
     minHeight:       480,
     frame:           true,
-    titleBarStyle:   'hidden',
+    titleBarStyle:   isMac ? 'hidden' : 'hiddenInset',
+    titleBarOverlay: isMac ? false : {
+      color:       '#0a0a0a',
+      symbolColor: '#8B5CF6',   // mauve — Water brand
+      height:      28,
+    },
     backgroundColor: '#0a0a0a',
     title:           'Water Morph',
     skipTaskbar:     false,
@@ -149,6 +158,11 @@ function handleLine(conn, line) {
     // The companion still sends OK to keep the plugin happy.
     conn.write('OK\n')
 
+  } else if (line === 'SHOW_WINDOW') {
+    // Plugin clicked "Open Water" — bring companion window to front
+    if (win) { win.show(); win.focus() }
+    conn.write('OK\n')
+
   } else if (line.startsWith('SYNC ')) {
     const parts = line.slice(5).split(' ')
     const bpm   = parseFloat(parts[0] || '0') || 0

Source/CompanionLink.cpp

@@ -1,7 +1,6 @@
 #include "CompanionLink.h"
 
-static constexpr int kPort      = 59812;
-static constexpr int kTimeoutMs = 3000;
+static constexpr int kPort = 59812;
 
 //==============================================================================
 CompanionLink& CompanionLink::get()
@@ -18,17 +17,24 @@ CompanionLink::~CompanionLink()
 //==============================================================================
 bool CompanionLink::tryConnect()
 {
+    // Throttle reconnect attempts to prevent blocking the message thread.
+    // kConnectTimeoutMs is only 200ms but we still cap to once every 5s.
+    const int64_t now = juce::Time::currentTimeMillis();
+    if (now - lastConnectAttemptMs_ < kReconnectThrottleMs)
+        return false;
+    lastConnectAttemptMs_ = now;
+
     disconnect();
     socket = std::make_unique<juce::StreamingSocket>();
 
-    if (! socket->connect ("127.0.0.1", kPort, kTimeoutMs))
+    if (! socket->connect ("127.0.0.1", kPort, kConnectTimeoutMs))
     {
         socket.reset();
         return false;
     }
 
     // Wait for READY\n handshake
-    if (socket->waitUntilReady (true, kTimeoutMs) != 1)
+    if (socket->waitUntilReady (true, kConnectTimeoutMs) != 1)
     {
         socket.reset();
         return false;
@@ -42,6 +48,8 @@ bool CompanionLink::tryConnect()
         return false;
     }
 
+    // Reset throttle on success so a reconnect after disconnect is instant
+    lastConnectAttemptMs_ = 0;
     return true;
 }
 
@@ -114,6 +122,23 @@ void CompanionLink::sendTransport (bool playing, double timeSecs, double ppq)
         disconnect();
 }
 
+//==============================================================================
+void CompanionLink::requestShowWindow()
+{
+    if (! isConnected()) tryConnect();
+    if (! isConnected())
+    {
+        // Companion not running — launch it via registered watermorph:// protocol.
+        // The companion registered itself as the handler at install time.
+        juce::URL ("watermorph://show").launchInDefaultBrowser();
+        return;
+    }
+
+    const juce::String cmd = "SHOW_WINDOW\n";
+    if (socket->write (cmd.toRawUTF8(), (int) cmd.getNumBytesAsUTF8()) <= 0)
+        disconnect();
+}
+
 //==============================================================================
 bool CompanionLink::isConnected() const noexcept
 {

Source/CompanionLink.h

@@ -48,6 +48,12 @@ class CompanionLink
     //==========================================================================
     void sendTransport (bool playing, double timeSecs, double ppq = 0.0);
 
+    //==========================================================================
+    // Ask the companion to bring its window to front.
+    // Falls back gracefully if companion is not running.
+    //==========================================================================
+    void requestShowWindow();
+
     //==========================================================================
     bool isConnected() const noexcept;
 
@@ -57,6 +63,12 @@ class CompanionLink
 
     std::unique_ptr<juce::StreamingSocket> socket;
 
+    // Throttle reconnect attempts — tryConnect() blocks for kConnectTimeoutMs,
+    // so we cap retries to once every kReconnectThrottleMs to avoid UI freeze.
+    int64_t lastConnectAttemptMs_ { 0 };
+    static constexpr int kConnectTimeoutMs    =  200;   // was 3000 — prevents UI freeze
+    static constexpr int kReconnectThrottleMs = 5000;   // retry at most every 5 s
+
     bool tryConnect();
     void disconnect();
 

Source/PluginEditor.cpp

@@ -254,7 +254,9 @@ void MorphAudioProcessorEditor::mouseUp (const juce::MouseEvent& e)
 
     if (helpRect_.contains (pt))
     {
-        juce::URL ("https://water.95ent.ai").launchInDefaultBrowser();
+        // Show the companion window (Electron app). Falls back to watermorph://
+        // protocol if companion is not connected, which launches it if installed.
+        CompanionLink::get().requestShowWindow();
         return;
     }