[EXPERIMENT — DO NOT MERGE] Linux buddy floater via XWayland

desktop/package.json

@@ -6,7 +6,7 @@
   "main": "dist/main/main.js",
   "scripts": {
     "dev": "node scripts/run-dev.js",
-    "dev:main": "tsc -p tsconfig.json && node -e \"require('fs').cpSync('src/main/pty-worker.js','dist/main/pty-worker.js')\" && electron .",
+    "dev:main": "tsc -p tsconfig.json && node -e \"require('fs').cpSync('src/main/pty-worker.js','dist/main/pty-worker.js')\" && electron . --ozone-platform=x11",
     "dev:renderer": "vite",
     "build": "tsc && node -e \"require('fs').cpSync('src/main/pty-worker.js','dist/main/pty-worker.js')\" && node -e \"require('fs').mkdirSync('dist/renderer/data',{recursive:true})\" && node -e \"require('fs').cpSync('src/renderer/data/skill-registry.json','dist/renderer/data/skill-registry.json')\" && vite build && electron-builder",
     "test": "vitest",

desktop/src/main/buddy-window-manager.ts

@@ -236,9 +236,10 @@ export class BuddyWindowManager {
       for (const leg of legs) {
         if (leg.win.isDestroyed()) continue;
         alive = true;
-        leg.win.setPosition(
-          Math.round(leg.from.x + (leg.to.x - leg.from.x) * ease),
-          Math.round(leg.from.y + (leg.to.y - leg.from.y) * ease),
+        this.place(
+          leg.win,
+          leg.from.x + (leg.to.x - leg.from.x) * ease,
+          leg.from.y + (leg.to.y - leg.from.y) * ease,
         );
       }
       if (t >= 1 || !alive) {
@@ -321,7 +322,7 @@ export class BuddyWindowManager {
       const mb = this.mascot.getBounds();
       const d = screen.getDisplayMatching(mb) ?? screen.getPrimaryDisplay();
       const flush = dockPosition(savedEdge, { x: mb.x, y: mb.y }, MASCOT_SIZE, d.workArea);
-      this.mascot.setPosition(Math.round(flush.x), Math.round(flush.y));
+      this.place(this.mascot, flush.x, flush.y);
       // A buddy put away on an edge comes back put away — peeking is the
       // resting state at an edge now, not a timer's eventual destination.
       this.dockState = { mode: 'peeking', edge: savedEdge };
@@ -411,7 +412,7 @@ export class BuddyWindowManager {
       // position.
       this.chatOpenIntent = true;
       const layout = this.layoutFor();
-      this.chat.setPosition(Math.round(layout.chat.x), Math.round(layout.chat.y));
+      this.place(this.chat, layout.chat.x, layout.chat.y);
       this.chat.show();
       this.chat.webContents.send(IPC_CHAT_STATE, { visible: true });
       this.barVisibility.setChatOpen(true);
@@ -475,6 +476,37 @@ export class BuddyWindowManager {
   getChatWindow(): BrowserWindow | null { return this.chat; }
   getBarWindow(): BrowserWindow | null { return this.bar; }
 
+  /**
+   * Move a buddy window, re-asserting its fixed size on Linux.
+   *
+   * WHY: on XWayland with fractional display scaling (e.g. KDE at 1.5×),
+   * Electron's setPosition() inflates a frameless window's size by a
+   * DIP↔physical rounding error on EVERY call. Probe-confirmed: a 334×490
+   * window grew to 373×529 after 40 setPosition calls (setBounds with the fixed
+   * size pins it; setMinimumSize/setMaximumSize do NOT). moveMascot fires one
+   * setPosition per pointermove, so across a real drag the chat ballooned past
+   * the whole screen (measured 1851×1526) and the three windows drifted apart —
+   * this is the "chat keeps getting bigger / doesn't stay together" jank.
+   * Re-asserting the size via setBounds every move stops the accumulation. We
+   * only do this on Linux so Windows/macOS keep the cheaper setPosition path
+   * (its DWM cost is noted in moveMascot) where no inflation occurs. The size
+   * comes from the same constants main.ts builds the windows with, so
+   * re-asserting it is always exact.
+   */
+  private place(win: BrowserWindow, x: number, y: number): void {
+    const rx = Math.round(x);
+    const ry = Math.round(y);
+    const size =
+      win === this.mascot ? MASCOT_SIZE :
+      win === this.chat ? CHAT_SIZE :
+      win === this.bar ? BAR_SIZE : null;
+    if (process.platform === 'linux' && size) {
+      win.setBounds({ x: rx, y: ry, width: size.width, height: size.height });
+    } else {
+      win.setPosition(rx, ry);
+    }
+  }
+
   /**
    * Place the mascot at an anchor-based target position from the renderer
    * (cursor screenX/Y minus the grab offset captured on pointerdown). Clamps
@@ -518,7 +550,7 @@ export class BuddyWindowManager {
         this.closeChat(); // fades chat + bar out; chatOpenIntent flips false now
         this.dispatchDock({ type: 'drag-peek', edge: shove });
         const pos = dockPosition(shove, clamped, MASCOT_SIZE, wa);
-        this.mascot.setPosition(Math.round(pos.x), Math.round(pos.y));
+        this.place(this.mascot, pos.x, pos.y);
         return;
       }
       if (this.dockState.mode !== 'free') this.dispatchDock({ type: 'drag-start' });
@@ -540,7 +572,7 @@ export class BuddyWindowManager {
       if (edge) {
         this.dispatchDock({ type: 'drag-peek', edge });
         const pos = dockPosition(edge, clamped, MASCOT_SIZE, wa);
-        this.mascot.setPosition(Math.round(pos.x), Math.round(pos.y));
+        this.place(this.mascot, pos.x, pos.y);
         return; // flush against the edge; chat closed → no satellites to follow
       }
       this.dispatchDock({ type: 'drag-start' }); // in open space → free/idle
@@ -551,7 +583,7 @@ export class BuddyWindowManager {
     // conversion failure" from Electron's native bridge.
     const newX = Math.round(clamped.x);
     const newY = Math.round(clamped.y);
-    this.mascot.setPosition(newX, newY);
+    this.place(this.mascot, newX, newY);
     // Move the chat by the SAME delta the mascot actually moved (not the
     // requested delta, which may have been clamped). Clamp the follow-
     // position to the chat's own display's workArea — the mascot may be
@@ -571,15 +603,15 @@ export class BuddyWindowManager {
       const chatRaw = { x: cb.x + actualDx, y: cb.y + actualDy };
       const chatDisplay = screen.getDisplayMatching({ ...chatRaw, ...CHAT_SIZE }) ?? screen.getPrimaryDisplay();
       const chatClamped = clampToWorkArea(chatRaw, CHAT_SIZE, chatDisplay.workArea);
-      this.chat.setPosition(Math.round(chatClamped.x), Math.round(chatClamped.y));
+      this.place(this.chat, chatClamped.x, chatClamped.y);
     }
     // Bar follows its own CSS visibility (not Electron isVisible() — the
     // window stays Electron-shown once created; reveals are CSS fades).
     // Recompute from scratch on visible: if the mascot lands on a bottom
     // edge the bar needs to flip above automatically.
     if (this.bar && !this.bar.isDestroyed() && this.barCssVisible) {
       const pos = this.currentBarPosition();
-      this.bar.setPosition(Math.round(pos.x), Math.round(pos.y));
+      this.place(this.bar, pos.x, pos.y);
     }
   }
 
@@ -601,7 +633,7 @@ export class BuddyWindowManager {
         }
       });
     } else {
-      this.bar.setPosition(Math.round(pos.x), Math.round(pos.y));
+      this.place(this.bar, pos.x, pos.y);
     }
     if (!this.bar.isVisible()) this.bar.showInactive();
   }

desktop/src/main/main.ts

@@ -67,6 +67,63 @@ import { cleanupStaleDownloads } from './update-installer';
 import { runAnalyticsOnLaunch } from './analytics-service';
 import { loadConfigSync, setAppliedAtLaunch, setCachedGpu } from './performance-config';
 
+// Route Linux Wayland sessions through XWayland.  *** EXPERIMENTAL — NOT
+// PRODUCTION-READY *** (see the PR / investigation doc; shelved 2026-07-23).
+//
+// WHY: native Wayland forbids a client from positioning its own windows, and
+// the buddy floater's entire model is main-process setPosition per drag frame.
+// On Wayland every one of those calls is silently dropped — worse, getPosition()
+// echoes back the value you asked for, so the app cannot even detect the
+// failure. Probed against KWin 6.7.3 / Electron 41.0.3 on 2026-07-22
+// (docs/active/prototypes/2026-07-22-buddy-wayland-workbench/FINDINGS.md):
+//
+//                        native Wayland          XWayland
+//   setPosition()        no-op (reports success) works
+//   getCursorScreenPoint {0,0}                   real coords
+//   always-on-top        KWin keepAbove=false    KWin keepAbove=true
+//   transparency         froze opaque 0/10       stable 10/10
+//
+// The 2026-07-17 rejection of XWayland assumed it renders blurry at fractional
+// scaling. That was wrong on THIS setup: KDE's [Xwayland] Scale makes KWin hand
+// X11 clients native resolution, so Electron reports devicePixelRatio 1.5 and
+// renders at full 2560x1600. (Sharpness is compositor-specific — it can still
+// be blurry on GNOME / other fractional-scale setups. One of several reasons
+// this stays experimental.)
+//
+// *** KNOWN GAP (verified 2026-07-23) — this appendSwitch DOES NOT WORK. ***
+// app.commandLine.appendSwitch('ozone-platform', 'x11') is silently ineffective
+// on Electron 41: the process still comes up on the native Wayland ozone
+// backend (confirmed by the ui/ozone/platform/wayland/* init logs and KWin
+// reporting the windows as native, surface!=null). ELECTRON_OZONE_PLATFORM_HINT
+// was also ineffective. The ONLY mechanism that actually forced XWayland was a
+// real argv flag on the electron binary: `electron . --ozone-platform=x11`.
+// For dev that flag is injected by the `dev:main` npm script on this branch;
+// production enablement would need the app to re-exec itself with the flag (or a
+// launcher/.desktop entry that carries it) — NOT YET IMPLEMENTED. The block
+// below is kept as intent + kill switch, but on its own it changes nothing.
+//
+// Kill switch: YOUCODED_OZONE=wayland forces the native backend back on.
+if (process.platform === 'linux' && !app.isReady()) {
+  const ozoneOverride = process.env.YOUCODED_OZONE;
+  const isWaylandSession =
+    process.env.XDG_SESSION_TYPE === 'wayland' || !!process.env.WAYLAND_DISPLAY;
+  if (ozoneOverride) {
+    app.commandLine.appendSwitch('ozone-platform', ozoneOverride);
+  } else if (isWaylandSession) {
+    app.commandLine.appendSwitch('ozone-platform', 'x11'); // see KNOWN GAP above
+  }
+  // GPU-crash workaround (verified 2026-07-23): under XWayland the GPU process
+  // SIGSEGVs (exit_code=139) inside bundled ANGLE at EGL_CreateWindowSurface on
+  // this machine's AMD/mesa stack — the default GL backend crashed 3× on every
+  // launch. YOUCODED_ANGLE=vulkan routed ANGLE through Vulkan (RADV) and
+  // eliminated the crash entirely (0 vs 3). This is machine-specific: other GPUs
+  // (Nvidia/Intel/older mesa) may need a different backend, so we do NOT default
+  // it — it must be passed explicitly (YOUCODED_ANGLE=vulkan|swiftshader|gl).
+  if (process.env.YOUCODED_ANGLE) {
+    app.commandLine.appendSwitch('use-angle', process.env.YOUCODED_ANGLE);
+  }
+}
+
 // macOS and Linux Electron apps may inherit a minimal PATH that's missing
 // common tool locations (Homebrew, nvm, Volta, pipx, cargo). macOS Finder/Dock
 // only provides /usr/bin:/bin:/usr/sbin:/sbin. Linux Snap/Flatpak/some DEs may

desktop/tests/ipc-handlers.test.ts

@@ -6,7 +6,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 vi.mock('electron', () => ({
   // whenReady must never resolve — otherwise main.ts runs its entire init chain
   // (createWindow, RemoteServer, SyncService, etc.) which hits unmocked APIs.
-  app: { isPackaged: false, getPath: vi.fn(() => '/tmp'), getVersion: vi.fn(() => '0.0.0-test'), whenReady: vi.fn(() => new Promise(() => {})), on: vi.fn(), quit: vi.fn(), setAppUserModelId: vi.fn(), commandLine: { appendSwitch: vi.fn() }, getGPUInfo: vi.fn(() => new Promise(() => {})) },
+  app: { isPackaged: false, isReady: vi.fn(() => false), getPath: vi.fn(() => '/tmp'), getVersion: vi.fn(() => '0.0.0-test'), whenReady: vi.fn(() => new Promise(() => {})), on: vi.fn(), quit: vi.fn(), setAppUserModelId: vi.fn(), commandLine: { appendSwitch: vi.fn() }, getGPUInfo: vi.fn(() => new Promise(() => {})) },
   ipcMain: { handle: vi.fn(), on: vi.fn() },
   BrowserWindow: vi.fn(() => ({ loadURL: vi.fn(), on: vi.fn(), webContents: { send: vi.fn() } })),
   Menu: { setApplicationMenu: vi.fn() },

desktop/tests/session-meta-native-refusal.test.ts

@@ -23,7 +23,7 @@ import os from 'node:os';
 import path from 'node:path';
 
 vi.mock('electron', () => ({
-  app: { isPackaged: false, getPath: vi.fn(() => '/tmp'), getVersion: vi.fn(() => '0.0.0-test'), whenReady: vi.fn(() => new Promise(() => {})), on: vi.fn(), quit: vi.fn(), setAppUserModelId: vi.fn(), commandLine: { appendSwitch: vi.fn() }, getGPUInfo: vi.fn(() => new Promise(() => {})) },
+  app: { isPackaged: false, isReady: vi.fn(() => false), getPath: vi.fn(() => '/tmp'), getVersion: vi.fn(() => '0.0.0-test'), whenReady: vi.fn(() => new Promise(() => {})), on: vi.fn(), quit: vi.fn(), setAppUserModelId: vi.fn(), commandLine: { appendSwitch: vi.fn() }, getGPUInfo: vi.fn(() => new Promise(() => {})) },
   ipcMain: { handle: vi.fn(), on: vi.fn() },
   BrowserWindow: vi.fn(() => ({ loadURL: vi.fn(), on: vi.fn(), webContents: { send: vi.fn() } })),
   Menu: { setApplicationMenu: vi.fn() },