fix(desktop): support Linux distro protocol launchers

apps/desktop/src/app/DesktopConfig.ts

@@ -55,6 +55,7 @@ export const DesktopConfig = Config.all({
   otlpProtocol: Config.schema(OtlpProtocol, "T3CODE_OTLP_PROTOCOL").pipe(
     Config.withDefault("http/json"),
   ),
+  desktopLauncherPath: trimmedString("T3CODE_DESKTOP_LAUNCHER_PATH"),
   appImagePath: trimmedString("APPIMAGE"),
   disableAutoUpdate: optionalBoolean("T3CODE_DISABLE_AUTO_UPDATE"),
   mockUpdates: optionalBoolean("T3CODE_DESKTOP_MOCK_UPDATES"),

apps/desktop/src/app/DesktopEnvironment.ts

@@ -85,6 +85,7 @@ export class DesktopEnvironment extends Context.Service<
     readonly linuxDesktopEntryName: string;
     readonly linuxWmClass: string;
     readonly linuxApplicationsDir: string;
+    readonly desktopLauncherPath: Option.Option<string>;
     readonly appImagePath: Option.Option<string>;
     readonly userDataDirName: string;
     readonly legacyUserDataDirName: string;
@@ -245,6 +246,7 @@ const make = Effect.fn("desktop.environment.make")(function* (
     linuxDesktopEntryName: resolveLinuxDesktopEntryName(isDevelopment),
     linuxWmClass: isDevelopment ? "t3code-dev" : "t3code",
     linuxApplicationsDir,
+    desktopLauncherPath: config.desktopLauncherPath,
     appImagePath: config.appImagePath,
     userDataDirName,
     legacyUserDataDirName,

apps/desktop/src/app/DesktopLinuxUrlHandler.test.ts

@@ -32,6 +32,7 @@ const makeEnvironment = (path: Path.Path, overrides: Record<string, unknown> = {
     linuxDesktopEntryName: "com.t3tools.T3Code.desktop",
     linuxWmClass: "t3code",
     linuxApplicationsDir: "/home/alice/.local/share/applications",
+    desktopLauncherPath: Option.none(),
     appImagePath: Option.some("/home/alice/Applications/T3-Code.AppImage"),
     path,
     ...overrides,
@@ -254,6 +255,18 @@ describe("DesktopLinuxUrlHandler", () => {
     });
   });
 
+  it.effect("launches a distribution package through its own launcher", () => {
+    const recorded = emptyRecording();
+
+    return Effect.gen(function* () {
+      yield* runRegister(recorded, {
+        environment: { desktopLauncherPath: Option.some("/usr/bin/t3code") },
+      });
+
+      assert.include(recorded.files[0]?.content, 'Exec="/usr/bin/t3code" %U');
+    });
+  });
+
   it.effect("does not rewrite the pre-ready entry while the portal can be reading it", () => {
     const recorded = emptyRecording();
 

apps/desktop/src/app/DesktopLinuxUrlHandler.ts

@@ -126,9 +126,14 @@ export const make = Effect.gen(function* () {
   const iconPath = environment.path.join(iconsDir, `${environment.linuxDesktopEntryName}.png`);
 
   const writeDesktopEntry = Effect.gen(function* () {
-    // Inside the mounted AppImage, process.execPath points at a transient
-    // /tmp/.mount_* path — the handler must launch the AppImage itself.
-    const execTarget = Option.getOrElse(environment.appImagePath, () => process.execPath);
+    // Distribution packages run the app on a shared Electron, so process.execPath
+    // is that Electron rather than their launcher. Inside the mounted AppImage,
+    // process.execPath points at a transient /tmp/.mount_* path — the handler
+    // must launch the AppImage itself.
+    const execTarget = environment.desktopLauncherPath.pipe(
+      Option.orElse(() => environment.appImagePath),
+      Option.getOrElse(() => process.execPath),
+    );
     const content = renderUrlHandlerDesktopEntry({
       displayName: environment.displayName,
       execTarget,

apps/desktop/src/app/DesktopPreReadyPlatform.test.ts

@@ -156,6 +156,18 @@ describe("DesktopPreReadyPlatform", () => {
     }).pipe(Effect.provideService(HostProcessPlatform, "linux"));
   });
 
+  it.effect("points the early portal entry at a distribution launcher", () => {
+    vi.stubEnv("T3CODE_DESKTOP_LAUNCHER_PATH", " /usr/bin/t3code ");
+    getSwitchValueMock.mockReturnValue("");
+    return Effect.gen(function* () {
+      yield* DesktopPreReadyPlatform.make;
+      assert.include(writeFileSyncMock.mock.calls[0]?.[1], 'Exec="/usr/bin/t3code" %U');
+    }).pipe(
+      Effect.provideService(HostProcessPlatform, "linux"),
+      Effect.ensuring(Effect.sync(() => vi.unstubAllEnvs())),
+    );
+  });
+
   it.effect(
     "acquires a synchronous pre-ready layer before an asynchronous Clerk-shaped layer",
     () =>

apps/desktop/src/app/DesktopPreReadyPlatform.ts

@@ -97,7 +97,10 @@ export const make = Effect.gen(function* () {
               isDevelopment: linux.isDevelopment,
               appVersion: Electron.app.getVersion(),
             }).displayName,
-            execTarget: process.env.APPIMAGE?.trim() || process.execPath,
+            execTarget:
+              process.env.T3CODE_DESKTOP_LAUNCHER_PATH?.trim() ||
+              process.env.APPIMAGE?.trim() ||
+              process.execPath,
             scheme: ElectronProtocol.getDesktopScheme(linux.isDevelopment),
             ...(iconPath === undefined ? {} : { iconPath }),
           }),