ci: link desktop installers instead of attaching them

.claude/skills/releasing-healthchat/SKILL.md

@@ -19,16 +19,19 @@ Releases are driven by git tags of the form `healthchat-v<semver>` pushed to
   `:<sha>`, so you can deploy them deliberately by overriding the image ref (see
   "Deploying the release"), but they can never become production by accident.
 - `.github/workflows/build-healthchat-desktop.yaml` (desktop) — builds the Electron
-  app for macOS (universal, signed+notarised) and Windows (x64/arm64, signed), and
-  attaches the installers (.dmg/.zip/.exe/.msi) to the **same** GitHub Release. The two
-  workflows create-if-missing then upload, so they race safely. (Linux is intentionally
-  not built — the upstream Linux reusable pulls a build-env Docker image keyed by commit
-  SHA that only exists in the upstream element-hq registry, so it cannot succeed in this
-  fork.) The `release` job also **stages** the Squirrel update feed and public installers and
-  attaches them to the Release as `healthchat-desktop-feed-<version>.tar.gz` — but it
-  **does not publish them**. See "Deploying the desktop release" below.
+  app for macOS (universal, signed+notarised) and Windows (x64/arm64, signed) and
+  publishes to the **same** GitHub Release as the web workflow (both create-if-missing,
+  so they race safely). (Linux is intentionally not built — the upstream Linux reusable
+  pulls a build-env Docker image keyed by commit SHA that only exists in the upstream
+  element-hq registry, so it cannot succeed in this fork.) The `release` job **stages**
+  the Squirrel update feed and public installers and attaches them to the Release as
+  split `healthchat-desktop-feed-<version>.tar.gz.part*` assets (the compressed feed
+  exceeds GitHub's 2 GiB per-asset cap) — but it **does not publish them**. Installer
+  binaries are not attached individually; the Release notes get a "## Downloads"
+  section linking their public URLs on packages.healthchat.ch, which resolve once the
+  version is deployed. See "Deploying the desktop release" below.
 - `.github/workflows/deploy-healthchat-desktop.yaml` (desktop deploy) — **manual
-  dispatch only.** Downloads that tarball and mirrors it to
+  dispatch only.** Downloads and reassembles those feed parts and mirrors the feed to
   `https://packages.healthchat.ch/desktop/` over FTPS (the private GitHub Release can
   serve neither end users nor the auto-updater), plus the legacy
   `https://healthchat.ch/packages/desktop/` path while clients built <= 1.5.0 are still
@@ -37,8 +40,8 @@ Releases are driven by git tags of the form `healthchat-v<semver>` pushed to
   the two caveats (first install is manual; Windows auto-update needs the Setup.exe path,
   not the .msi).
 
-Publish target: **ghcr.io Docker image + GitHub Release (web bundle + desktop
-installers).** No npm, no mobile fan-out.
+Publish target: **ghcr.io Docker image + GitHub Release (web bundle + desktop feed
+parts, with installer download links).** No npm, no mobile fan-out.
 
 ## Release ≠ deploy
 
@@ -186,7 +189,8 @@ run or `:latest` had not moved yet.
 
 ## Deploying the desktop release
 
-The desktop build attaches `healthchat-desktop-feed-<version>.tar.gz` to the Release but
+The desktop build attaches the split `healthchat-desktop-feed-<version>.tar.gz.part*`
+assets to the Release but
 leaves `https://packages.healthchat.ch/desktop/` untouched. Until you run this, installed
 apps keep whatever version they have and the public download links still serve the old
 installers.
@@ -319,9 +323,10 @@ warning. Prefer fixing the changelog over relying on the fallback.
       For an `-rc`/`-hotfix`/`-dryrun` tag the opposite is expected: `:latest` must
       be **unchanged**.
 - [ ] The desktop workflow run ("Build HealthChat Desktop") is green and the
-      GitHub Release has the desktop installers attached (.dmg, *-mac.zip, *.msi,
-      "* Setup*.exe") **plus** `healthchat-desktop-feed-<version>.tar.gz`. Without that
-      tarball the desktop deploy has nothing to publish.
+      GitHub Release carries the split feed assets
+      `healthchat-desktop-feed-<version>.tar.gz.part*` plus a "## Downloads" section
+      in its notes linking the public installers. Without those parts the desktop
+      deploy has nothing to publish.
 - [ ] Confirm the live feed is still on the **previous** version — releasing must not have
       moved it. `curl -fsS https://packages.healthchat.ch/desktop/update/macos/releases.json`
 - [ ] Smoke-check signing before shipping to users: macOS `spctl -a -vvv -t install <app>`