Packaging: build targets + Linux update-ping (v1.0.0)

- electron-builder: linux targets = deb, flatpak, tar.gz, pacman; win = nsis.
- updater.ts: Linux is notify-only (deb/pacman are package-manager owned,
  flatpak is sandboxed) — reads the same Codeberg feed as Windows and shows a
  "Blap X is available" desktop notification linking to HOW-TO-UPDATE.md.
  Windows/macOS keep electron-updater in-place install.
- HOW-TO-UPDATE.md: per-format update instructions.

Version stays 1.0.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

HOW-TO-UPDATE.md

@@ -0,0 +1,35 @@
+# Updating Blap
+
+All builds are published on the **[Blap releases page](https://codeberg.org/Enkisu/Blap/releases)**.
+Grab the newest file for your platform below.
+
+## Windows
+Automatic — when a new version is out, Blap shows a **"New update"** prompt; click it and Blap
+updates itself. (Or download the latest `Blap Setup X.Y.Z.exe` and run it.)
+
+## Linux
+Blap can't update itself on Linux (packages are owned by your package manager / the flatpak
+sandbox), so it just **notifies** you — then you update with one command for your format:
+
+### Flatpak (Bazzite, etc.)
+Download the new `Blap-X.Y.Z-x86_64.flatpak` and:
+```
+flatpak install --user Blap-X.Y.Z-x86_64.flatpak
+```
+(installing the newer bundle upgrades the existing install)
+
+### Debian / Ubuntu (`.deb`)
+```
+sudo apt install ./blap_X.Y.Z_amd64.deb
+```
+
+### Arch (`.pacman`)
+```
+sudo pacman -U blap-X.Y.Z.pacman
+```
+
+### Portable (`.tar.gz`)
+Extract the new tarball over your existing copy and run the `blap` executable — no install needed.
+
+---
+_Replace `X.Y.Z` with the version from the [releases page](https://codeberg.org/Enkisu/Blap/releases)._

apps/desktop/electron-builder.ts

@@ -138,8 +138,7 @@ const config: Omit<Writable<Configuration>, "electronFuses"> & {
         channel: "latest",
     },
     linux: {
-        // AppImage is the only Linux format electron-updater can auto-update in-app.
-        target: ["tar.gz", "deb", "AppImage"],
+        target: ["deb", "flatpak", "tar.gz", "pacman"],
         category: "Network;InstantMessaging;Chat",
         icon: "icon.png",
         executableName: variant.name, // element-desktop or element-desktop-nightly
@@ -196,9 +195,8 @@ const config: Omit<Writable<Configuration>, "electronFuses"> & {
         badgeIcon: "build/icon.icon",
     },
     win: {
-        // NSIS is required for electron-updater auto-update on Windows (replaces
-        // the old Squirrel target). msi kept for manual/enterprise installs.
-        target: ["nsis", "msi"],
+        // NSIS = the .exe installer (also what electron-updater uses on Windows).
+        target: ["nsis"],
         signtoolOptions: {
             signingHashAlgorithms: ["sha256"],
         },

apps/desktop/src/updater.ts

@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
 */
 
-import { app, ipcMain } from "electron";
+import { app, ipcMain, Notification, shell } from "electron";
 // electron-updater is CommonJS; this is the documented ESM interop form.
 import electronUpdater, { type UpdateInfo } from "electron-updater";
 
@@ -14,6 +14,11 @@ const { autoUpdater } = electronUpdater;
 const UPDATE_POLL_INTERVAL_MS = 60 * 60 * 1000;
 const INITIAL_UPDATE_DELAY_MS = 30 * 1000;
 
+// Blap update feed (same Codeberg release the electron-builder `publish` config points at).
+const CODEBERG_BASE = "https://codeberg.org/Enkisu/Blap";
+const LINUX_FEED_URL = `${CODEBERG_BASE}/releases/latest/download/latest-linux.yml`;
+const HOWTO_UPDATE_URL = `${CODEBERG_BASE}/src/branch/main/HOW-TO-UPDATE.md`;
+
 function ipcChannelSendUpdateStatus(status: boolean | string): void {
     global.mainWindow?.webContents.send("check_updates", status);
 }
@@ -34,18 +39,56 @@ async function pollForUpdates(): Promise<void> {
     }
 }
 
+/** Compare dotted numeric versions; true if `latest` is strictly newer than `current`. */
+function isNewer(latest: string, current: string): boolean {
+    const l = latest.split(".").map((n) => parseInt(n, 10) || 0);
+    const c = current.split(".").map((n) => parseInt(n, 10) || 0);
+    for (let i = 0; i < Math.max(l.length, c.length); i++) {
+        const a = l[i] ?? 0;
+        const b = c[i] ?? 0;
+        if (a !== b) return a > b;
+    }
+    return false;
+}
+
+let lastLinuxNotifiedVersion: string | undefined;
+
+/**
+ * Linux notify-only update check.
+ *
+ * Linux builds can't self-install (deb/pacman are package-manager owned, flatpak
+ * is sandboxed), so instead of updating in place we read the same Codeberg feed
+ * the Windows updater uses and, if there's a newer version, show a desktop
+ * notification that opens HOW-TO-UPDATE.md (which has the per-format commands).
+ */
+async function checkLinuxUpdate(): Promise<void> {
+    try {
+        const res = await fetch(`${LINUX_FEED_URL}?t=${Date.now()}`);
+        if (!res.ok) return;
+        const text = await res.text();
+        const latest = /^version:\s*(.+)$/m.exec(text)?.[1]?.trim();
+        if (!latest || !isNewer(latest, app.getVersion())) return;
+        if (latest === lastLinuxNotifiedVersion) return; // don't nag every poll
+        lastLinuxNotifiedVersion = latest;
+        if (!Notification.isSupported()) return;
+        const notification = new Notification({
+            title: `Blap ${latest} is available`,
+            body: "Click to see how to update.",
+        });
+        notification.on("click", () => void shell.openExternal(HOWTO_UPDATE_URL));
+        notification.show();
+    } catch (e) {
+        console.log("Couldn't check for Linux update", e);
+    }
+}
+
 /**
  * Start the auto-updater.
  *
- * Uses electron-updater, which reads its feed from `app-update.yml` baked in at
- * package time from the electron-builder `publish` config (a Codeberg release
- * "latest/download" URL). No runtime feed URL is needed.
- *
- * Notes:
- *  - Only works for packaged builds (dev has no app-update.yml).
- *  - On Linux, electron-updater only supports AppImage; deb/flatpak update via
- *    their own channels, so this no-ops there.
- *  - macOS would need a signed build + zip target to update.
+ * Windows/macOS use electron-updater (reads its feed from `app-update.yml`, baked
+ * in at package time from the electron-builder Codeberg `publish` config), which
+ * downloads and installs in place. Linux uses a notify-only check (see above).
+ * Only runs for packaged builds (dev has no app-update.yml).
  */
 export async function start(): Promise<void> {
     if (!app.isPackaged) {
@@ -53,6 +96,13 @@ export async function start(): Promise<void> {
         return;
     }
 
+    if (process.platform === "linux") {
+        console.log("Starting Linux update notifier (notify-only)");
+        setTimeout(checkLinuxUpdate, INITIAL_UPDATE_DELAY_MS);
+        setInterval(checkLinuxUpdate, UPDATE_POLL_INTERVAL_MS);
+        return;
+    }
+
     console.log("Starting auto update via electron-updater");
 
     autoUpdater.autoDownload = true;
@@ -89,4 +139,8 @@ export async function start(): Promise<void> {
 }
 
 ipcMain.on("install_update", installUpdate);
-ipcMain.on("check_updates", pollForUpdates);
+ipcMain.on("check_updates", () => {
+    // Manual "check for updates" from the renderer.
+    if (process.platform === "linux") void checkLinuxUpdate();
+    else void pollForUpdates();
+});