feat(desktop): show what's changed in auto-update prompt

Publish HEALTHCHAT_CHANGES.md release notes into the update feeds so users
see what changed. macOS gets them natively via releases.json's notes field;
Windows fetches a published notes.txt, since Squirrel.Windows only delivers
releaseName through the update-downloaded event.

.github/workflows/build-healthchat-desktop.yaml

@@ -231,6 +231,12 @@ jobs:
         permissions:
             contents: write
         steps:
+            # Needed so the staging step can read HEALTHCHAT_CHANGES.md to extract release notes.
+            # Lands at the workspace root; download-artifact below writes to dist-artifacts/, no conflict.
+            - uses: actions/checkout@v4
+              with:
+                  persist-credentials: false
+
             - name: Download all build artifacts
               uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
               with:
@@ -269,11 +275,36 @@ jobs:
             - name: Stage update feed + public installers
               run: |
                   set -euo pipefail
+                  # --- Release notes: extract this version's section from HEALTHCHAT_CHANGES.md ---
+                  # Same extraction as build-healthchat.yaml (web). Surfaced to desktop users in the
+                  # auto-update "See changes" dialog: macOS reads it from releases.json's `notes`
+                  # field natively, Windows fetches notes.txt (Squirrel.Windows can't carry notes
+                  # through the update-downloaded event — only releaseName is available).
+                  VERSION="${GITHUB_REF_NAME#healthchat-v}"
+                  NOTES=$(awk -v ver="$VERSION" '
+                    /^## Changes in / {
+                      if (found) { exit }
+                      if ($0 ~ "## Changes in " ver "( |$|\\()") { found = 1; next }
+                    }
+                    found { print }
+                  ' HEALTHCHAT_CHANGES.md | sed '/^[[:space:]]*$/{N;/^\n$/D;}')
+                  if [[ -z "$NOTES" ]]; then
+                    NOTES="HealthChat ${VERSION} — automated build from ${GITHUB_REF_NAME}."
+                    echo "::warning::No HEALTHCHAT_CHANGES.md section found for $VERSION — using fallback"
+                  fi
+                  printf '%s\n' "$NOTES" > notes.txt
+                  echo "--- release notes ---"; cat notes.txt
+
                   # --- macOS update feed: releases.json (Squirrel.Mac manifest) + signed *-mac.zip payload ---
                   mkdir -p feed/update/macos feed/install/macos
                   test -f dist-artifacts/macos/releases.json || {
                     echo "::error::dist-artifacts/macos/releases.json missing (did the macos job get base-url?)"; exit 1; }
                   cp -v dist-artifacts/macos/releases.json feed/update/macos/
+                  # Splice the notes into the manifest: Squirrel.Mac maps updateTo.notes -> the
+                  # update-downloaded event's releaseNotes, which the renderer already renders.
+                  jq --rawfile notes notes.txt '.releases[0].updateTo.notes = $notes' \
+                    feed/update/macos/releases.json > feed/update/macos/releases.json.tmp
+                  mv feed/update/macos/releases.json.tmp feed/update/macos/releases.json
                   find dist-artifacts/macos -type f -iname '*-mac.zip' -exec cp -v {} feed/update/macos/ \;
                   # --- macOS installer: versioned .dmg + a stable "latest" copy ---
                   find dist-artifacts/macos -type f -iname '*.dmg' -exec cp -v {} feed/install/macos/ \;
@@ -284,6 +315,9 @@ jobs:
                     src="dist-artifacts/win-$arch"
                     [ -d "$src" ] || { echo "::error::$src missing"; exit 1; }
                     mkdir -p "feed/update/win32/$arch" "feed/install/win32/$arch"
+                    # Side-channel for release notes: the desktop main process fetches this and
+                    # populates releaseNotes itself, since Squirrel.Windows can't deliver them.
+                    cp -v notes.txt "feed/update/win32/$arch/notes.txt"
                     find "$src" -type f -iname 'RELEASES'      -exec cp -v {} "feed/update/win32/$arch/" \;
                     find "$src" -type f -iname '*-full.nupkg'  -exec cp -v {} "feed/update/win32/$arch/" \;
                     find "$src" -type f -iname '* Setup*.exe'  -exec cp -v {} "feed/install/win32/$arch/" \;

apps/desktop/src/updater.ts

@@ -78,6 +78,7 @@ export async function start(updateBaseUrl: string): Promise<void> {
     if (!updateBaseUrl.endsWith("/")) {
         updateBaseUrl = updateBaseUrl + "/";
     }
+    updateFeedBaseUrl = updateBaseUrl;
 
     try {
         let url: string;
@@ -184,6 +185,27 @@ interface ICachedUpdate {
     updateURL: string;
 }
 
+// The feed base URL passed to start(), retained so the update-downloaded handler can fetch
+// release notes out-of-band on Windows (see below).
+let updateFeedBaseUrl: string | undefined;
+
+// On Windows the autoUpdater never provides release notes: "With Squirrel.Windows only
+// releaseName is available" (https://www.electronjs.org/docs/latest/api/auto-updater). We
+// publish a notes.txt alongside the per-arch Squirrel feed and fetch it here so the renderer's
+// update toast can show "what's changed" the same way it does on macOS (where Squirrel.Mac
+// carries the notes natively via releases.json).
+async function fetchWindowsReleaseNotes(): Promise<string> {
+    if (process.platform !== "win32" || !updateFeedBaseUrl) return "";
+    try {
+        const res = await fetch(`${updateFeedBaseUrl}win32/${process.arch}/notes.txt`);
+        if (!res.ok) return "";
+        return await res.text();
+    } catch (err) {
+        console.log("Couldn't fetch Windows release notes", err);
+        return "";
+    }
+}
+
 // cache the latest update which has been downloaded as electron offers no api to read it
 let latestUpdateDownloaded: ICachedUpdate | undefined;
 autoUpdater
@@ -205,7 +227,13 @@ autoUpdater
     });
 
 autoUpdater.on("update-downloaded", (ev, releaseNotes, releaseName, releaseDate, updateURL) => {
-    // forward to renderer
+    void (async (): Promise<void> => {
-    latestUpdateDownloaded = { releaseNotes, releaseName, releaseDate, updateURL };
+        // Windows delivers no release notes via the event, so fetch them out-of-band.
-    global.mainWindow?.webContents.send("update-downloaded", latestUpdateDownloaded);
+        if (!releaseNotes) {
+            releaseNotes = await fetchWindowsReleaseNotes();
+        }
+        // forward to renderer
+        latestUpdateDownloaded = { releaseNotes, releaseName, releaseDate, updateURL };
+        global.mainWindow?.webContents.send("update-downloaded", latestUpdateDownloaded);
+    })();
 });