.gitea/workflows/build-app-preview.yml

@@ -361,7 +361,6 @@ jobs:
         run: |
           mkdir -p artifacts
           cp app/src-tauri/target/release/bundle/appimage/*.AppImage artifacts/ 2>/dev/null || true
-          cp app/src-tauri/target/release/bundle/appimage/*.zsync artifacts/ 2>/dev/null || true
           ls -la artifacts/
 
       # Assets, not workflow artifacts — see the note at the top of this file.

.gitea/workflows/build-app.yml

@@ -226,10 +226,23 @@ jobs:
       - name: Collect artifacts
         run: |
           mkdir -p artifacts
+          # The versioned AppImage only. The update channel's copy lives in
+          # bundle/appimage/update-channel/ precisely so this glob cannot pick
+          # it up and publish an 80 MB duplicate under a second name.
           cp app/src-tauri/target/release/bundle/appimage/*.AppImage artifacts/ 2>/dev/null || true
-          cp app/src-tauri/target/release/bundle/appimage/*.zsync artifacts/ 2>/dev/null || true
           ls -la artifacts/
 
+          # A green job that published nothing is the worst outcome available:
+          # the release exists, carries no AppImage, and nobody is told. The
+          # `|| true` above is there so a missing bundle does not mask the real
+          # error, which makes this check the thing that catches it.
+          shopt -s nullglob
+          collected=(artifacts/*)
+          if [ ${#collected[@]} -eq 0 ]; then
+            echo "No artifacts collected — the bundler produced nothing." >&2
+            exit 1
+          fi
+
       - name: Upload to Gitea release
         if: gitea.event_name == 'push'
         env:
@@ -312,7 +325,11 @@ jobs:
         if: gitea.event_name == 'push'
         env:
           GH_PAT: ${{ secrets.GH_PAT }}
-        run: bash scripts/publish-update-channel.sh artifacts
+          GITEA_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
+          GITEA_SHA: ${{ gitea.sha }}
+        run: |
+          bash scripts/publish-update-channel.sh \
+            app/src-tauri/target/release/bundle/appimage/update-channel
 
   build-macos:
     runs-on: macos-latest

scripts/finalize-appimage.sh

@@ -91,6 +91,11 @@ HOOK="apprun-hooks/triple-c-wayland-fallback.sh"
 APPIMAGE_TOOL_URL="https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-x86_64.AppImage"
 
 APP_ID="com.triple-c.desktop"
+# The channel pair lives in its own directory. Left beside the versioned image
+# they are picked up by the release job's `*.AppImage` glob, and every release
+# then carries an eighty-megabyte byte-identical duplicate under a second name
+# — which is exactly as confusing on a downloads page as it sounds.
+CHANNEL_DIR="update-channel"
 STABLE_NAME="Triple-C_x86_64.AppImage"
 UPDATE_TAG="linux-latest"
 UPDATE_INFO="zsync|https://github.com/shadowdao/triple-c/releases/download/${UPDATE_TAG}/${STABLE_NAME}.zsync"
@@ -98,8 +103,13 @@ CATEGORIES="Development;Utility;"
 
 repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 appdata_src="$repo_root/packaging/appimage/$APP_ID.appdata.xml"
+# appimagetool looks for `<desktop basename>.appdata.xml` and warns the
+# metadata is missing under any other name — while the script cheerfully
+# reported it present. The AppStream id inside the file is unchanged and is
+# what actually identifies the component; only the filename follows the tool.
+appdata_installed_as="Triple-C.appdata.xml"
 
-dir="${1:?usage: unbundle-wayland-client.sh <bundle/appimage directory>}"
+dir="${1:?usage: finalize-appimage.sh <bundle/appimage directory>}"
 cd "$dir"
 
 shopt -s nullglob
@@ -109,6 +119,14 @@ if [ ${#images[@]} -eq 0 ]; then
   echo "No .AppImage in $dir — nothing to do." >&2
   exit 0
 fi
+# Refused here rather than after the repack: with two present the old position
+# let the script download appimagetool, repack, overwrite the versioned
+# artifact and write the channel pair, *then* fail — and it silently picked
+# images[0], which is glob order, i.e. the older version.
+if [ ${#images[@]} -ne 1 ]; then
+  echo "Expected 1 AppImage in $dir, found ${#images[@]}: ${images[*]}" >&2
+  exit 1
+fi
 appimage="${images[0]}"
 here="$PWD"
 
@@ -120,15 +138,15 @@ echo "Inspecting $appimage"
 ( cd "$work" && "$here/$appimage" --appimage-extract >/dev/null )
 root="$work/squashfs-root"
 
-if [ ! -e "$root/usr/lib/$LIB" ]; then
-  # Not a failure: linuxdeploy may have stopped bundling it, which is the
-  # outcome this script exists to produce.
-  echo "$LIB is not bundled — leaving $appimage alone."
-  exit 0
-fi
+# The demotion and the metadata are independent jobs, and an absent library
+# must not skip the second. An early exit here also left `update-channel/`
+# uncreated, which killed the publish step on a missing directory and took the
+# tag and mirror jobs down with it — a half-published release.
+demoted=false
+if [ -e "$root/usr/lib/$LIB" ]; then
 
-mkdir -p "$root/$FALLBACK_DIR"
-mv "$root/usr/lib/$LIB" "$root/$FALLBACK_DIR/$LIB"
+  mkdir -p "$root/$FALLBACK_DIR"
+  mv "$root/usr/lib/$LIB" "$root/$FALLBACK_DIR/$LIB"
 
 cat > "$root/$HOOK" <<'HOOK_EOF'
 #! /usr/bin/env bash
@@ -177,6 +195,11 @@ src = src.replace(
 )
 open(path, "w").write(src)
 PATCH_EOF
+  fi
+  demoted=true
+  echo "Demoted $LIB to $FALLBACK_DIR."
+else
+  echo "$LIB is not bundled — nothing to demote."
 fi
 
 # --- metadata -------------------------------------------------------------
@@ -188,22 +211,29 @@ version="$(printf '%s' "$appimage" | sed -n 's/.*_\([0-9][0-9.]*\)_.*/\1/p')"
 if [ -f "$appdata_src" ]; then
   mkdir -p "$root/usr/share/metainfo"
   sed -e "s/@VERSION@/$version/" -e "s/@DATE@/$(date -u +%Y-%m-%d)/" \
-    "$appdata_src" > "$root/usr/share/metainfo/$APP_ID.appdata.xml"
+    "$appdata_src" > "$root/usr/share/metainfo/$appdata_installed_as"
   echo "Added AppStream metadata for $version."
 else
   echo "No AppStream source at $appdata_src — skipping." >&2
 fi
 
 # linuxdeploy emits `Categories=` empty, which files the app nowhere.
-for desktop in "$root"/*.desktop; do
+#
+# The AppDir root entry is a **symlink** into usr/share/applications, so a
+# plain `sed -i` replaces the link with a regular file and leaves the real entry
+# untouched — two divergent copies, of which the empty one is the one that
+# actually ships and the filled one is the only one a root-only guard can see.
+# `--follow-symlinks` writes through. Both locations are globbed because the
+# layout is linuxdeploy's, not ours, and it is free to stop symlinking.
+for desktop in "$root"/*.desktop "$root"/usr/share/applications/*.desktop; do
   [ -e "$desktop" ] || continue
   if grep -q "^Categories=$" "$desktop"; then
-    sed -i "s/^Categories=$/Categories=$CATEGORIES/" "$desktop"
-    echo "Filled in Categories for $(basename "$desktop")."
+    sed -i --follow-symlinks "s/^Categories=$/Categories=$CATEGORIES/" "$desktop"
+    echo "Filled in Categories for ${desktop#"$root"/}."
   fi
 done
 
-echo "Demoted $LIB to $FALLBACK_DIR; repacking."
+echo "Repacking."
 
 tool="$work/appimagetool"
 curl -fsSL -o "$tool" "$APPIMAGE_TOOL_URL"
@@ -211,13 +241,19 @@ chmod +x "$tool"
 
 # --appimage-extract-and-run: CI runners generally have no FUSE.
 # -u embeds the update string and writes "$STABLE_NAME.zsync" beside the image.
+rm -rf "$CHANNEL_DIR"
+mkdir -p "$CHANNEL_DIR"
 ARCH=x86_64 "$tool" --appimage-extract-and-run \
-  -u "$UPDATE_INFO" "$root" "$STABLE_NAME" >/dev/null
-chmod +x "$STABLE_NAME"
+  -u "$UPDATE_INFO" "$root" "$CHANNEL_DIR/$STABLE_NAME" >/dev/null
+chmod +x "$CHANNEL_DIR/$STABLE_NAME"
 
 # The versioned name is what the per-version release publishes; the stable one
-# and its .zsync go to the rolling tag. Same bytes, two names.
-cp "$STABLE_NAME" "$appimage"
+# and its .zsync go to the rolling tag. Same bytes, two names, two places.
+# zsyncmake writes the .zsync into the working directory, not beside the image
+# it describes, so it has to be collected rather than assumed in place.
+[ -e "$STABLE_NAME.zsync" ] && mv "$STABLE_NAME.zsync" "$CHANNEL_DIR/"
+
+cp "$CHANNEL_DIR/$STABLE_NAME" "$appimage"
 chmod +x "$appimage"
 
 # The guards are the test. Each one is a way the repack could look like it
@@ -227,16 +263,28 @@ out="$check/squashfs-root"
 
 fail() { echo "FAILED: $1" >&2; exit 1; }
 
-[ -e "$out/usr/lib/$LIB" ] && fail "$LIB is still on the loader path."
-[ -e "$out/$FALLBACK_DIR/$LIB" ] || fail "the fallback copy of $LIB is missing."
-[ -e "$out/$HOOK" ] || fail "the fallback hook is missing."
-grep -q "triple-c-wayland-fallback" "$out/AppRun" || fail "AppRun does not source the hook."
+if [ "$demoted" = true ]; then
+  [ -e "$out/usr/lib/$LIB" ] && fail "$LIB is still on the loader path."
+  [ -e "$out/$FALLBACK_DIR/$LIB" ] || fail "the fallback copy of $LIB is missing."
+  [ -e "$out/$HOOK" ] || fail "the fallback hook is missing."
+  grep -q "triple-c-wayland-fallback" "$out/AppRun" || fail "AppRun does not source the hook."
+fi
 [ -x "$out/usr/bin/triple-c" ] || fail "no executable usr/bin/triple-c."
 
 # An empty Categories or missing metadata ships an image a manager cannot file
 # or describe, and both fail silently at runtime rather than at build time.
-grep -q "^Categories=.\+" "$out"/*.desktop || fail "Categories is still empty."
-[ -f "$appdata_src" ] && { [ -e "$out/usr/share/metainfo/$APP_ID.appdata.xml" ] \
+# Asserted positively, over every entry: the earlier form checked only that no
+# *root* file held an empty value, which passed while the real entry under
+# usr/share/applications shipped empty, and also passed on a missing key.
+desktops=0
+for desktop in "$out"/*.desktop "$out"/usr/share/applications/*.desktop; do
+  [ -e "$desktop" ] || continue
+  desktops=$((desktops + 1))
+  grep -q "^Categories=$CATEGORIES$" "$desktop" \
+    || fail "${desktop#"$out"/} does not carry Categories=$CATEGORIES."
+done
+[ "$desktops" -gt 0 ] || fail "the image contains no .desktop entry at all."
+[ -f "$appdata_src" ] && { [ -e "$out/usr/share/metainfo/$appdata_installed_as" ] \
   || fail "AppStream metadata did not make it into the image."; }
 
 # The update string is the difference between adoptable and updatable. It
@@ -245,13 +293,25 @@ grep -q "^Categories=.\+" "$out"/*.desktop || fail "Categories is still empty."
 # the URL it fetched the .zsync from. That is exactly why the output is named
 # for the fixed tag: a versioned name here resolves to the build the client
 # already has.
-[ -e "$STABLE_NAME" ] || fail "the stable-named image is missing."
-[ -e "$STABLE_NAME.zsync" ] || fail "appimagetool wrote no $STABLE_NAME.zsync."
+[ -e "$CHANNEL_DIR/$STABLE_NAME" ] || fail "the stable-named image is missing."
+[ -e "$CHANNEL_DIR/$STABLE_NAME.zsync" ] || fail "appimagetool wrote no .zsync."
 
-readelf -p .upd_info "$STABLE_NAME" 2>/dev/null | grep -q "$UPDATE_TAG" \
-  || fail "the image carries no update information for the $UPDATE_TAG tag."
-grep -aq "^Filename: $STABLE_NAME$" "$STABLE_NAME.zsync" \
+readelf -p .upd_info "$CHANNEL_DIR/$STABLE_NAME" 2>/dev/null | grep -qF "$UPDATE_INFO" \
+  || fail "the image does not carry exactly the expected update information."
+grep -aq "^Filename: $STABLE_NAME$" "$CHANNEL_DIR/$STABLE_NAME.zsync" \
   || fail "the .zsync names something other than $STABLE_NAME."
 
-echo "OK: $appimage prefers the host $LIB (fallback kept), carries AppStream"
-echo "    metadata, and updates from the $UPDATE_TAG tag via $STABLE_NAME.zsync."
+# The versioned release must carry one AppImage, not two. This is the guard
+# for the duplicate that shipped in 0.4.20 and 0.4.21.
+shopt -s nullglob
+beside=(*.AppImage)
+shopt -u nullglob
+[ "${#beside[@]}" -eq 1 ] \
+  || fail "expected 1 AppImage beside the release, found ${#beside[@]}."
+
+if [ "$demoted" = true ]; then
+  echo "OK: $appimage prefers the host $LIB (fallback kept) and carries"
+else
+  echo "OK: $appimage had no bundled $LIB to demote, and carries"
+fi
+echo "    AppStream metadata. Channel pair in $CHANNEL_DIR/, updating from $UPDATE_TAG."

scripts/publish-update-channel.sh

@@ -17,7 +17,22 @@
 # It writes to GitHub rather than Gitea because that mirror is where updates
 # are pulled from. Needs GH_PAT with contents write on the mirror.
 #
-# Usage: GH_PAT=... publish-update-channel.sh <directory holding the artifacts>
+# **The tag has to exist in Gitea, not just on GitHub, and that is the whole
+# reason this script touches Gitea at all.** Gitea push-mirrors this repo to
+# GitHub, and a mirror push deletes remote refs that have no local counterpart.
+# A tag created only by GitHub's release API therefore survives until the next
+# mirror run and then vanishes — which is exactly what happened to 0.4.20 and
+# 0.4.21: the release was created and both URLs verified 200 at 00:38, and the
+# 13:04 mirror deleted the tag, leaving every installed copy checking a 404.
+# Versioned tags never had this problem because `create-tag` creates them in
+# Gitea first. So does this one, now, and before the GitHub release rather than
+# after, so there is no window where the two disagree.
+#
+# Note what this means for verification: publishing correctly is not evidence
+# the channel still works hours later. The Gitea tag is what makes it durable,
+# so its absence is treated as a failure rather than a warning.
+#
+# Usage: GH_PAT=... GITEA_TOKEN=... GITEA_SHA=... publish-update-channel.sh <dir>
 
 set -euo pipefail
 
@@ -26,7 +41,12 @@ TAG="linux-latest"
 API="https://api.github.com/repos/$REPO"
 ASSETS=("Triple-C_x86_64.AppImage" "Triple-C_x86_64.AppImage.zsync")
 
+GITEA_API="${GITEA_API:-https://repo.anhonesthost.net/api/v1}"
+GITEA_REPO="${GITEA_REPO:-CyberCoveLLC/Triple-C}"
+
 : "${GH_PAT:?GH_PAT is required to publish the update channel}"
+: "${GITEA_TOKEN:?GITEA_TOKEN is required to anchor the $TAG tag against the mirror}"
+: "${GITEA_SHA:?GITEA_SHA is required to point the $TAG tag at this build}"
 dir="${1:?usage: publish-update-channel.sh <artifacts directory>}"
 cd "$dir"
 
@@ -35,46 +55,179 @@ for asset in "${ASSETS[@]}"; do
 done
 
 gh() { curl -sf -H "Authorization: Bearer $GH_PAT" -H "Accept: application/vnd.github+json" "$@"; }
+tea() { curl -sf -H "Authorization: token $GITEA_TOKEN" -H "Content-Type: application/json" "$@"; }
+# Status, not a boolean. `curl -sf` fails identically for "404, the tag is
+# genuinely absent" and "503, Gitea is briefly unreachable", and treating the
+# second as the first means POSTing over a tag that already exists, taking a
+# 409, and aborting the last step of build-linux — which `create-tag` and
+# `sync-to-github` both depend on. A transient blip would cost the release, not
+# just the channel update. Same `case`-on-code idiom as `Upload to Gitea
+# release` two steps above in the workflow. A refused connection reports 000
+# and lands in the catch-all.
+tea_code() { curl -s -o /dev/null -w '%{http_code}' -H "Authorization: token $GITEA_TOKEN" "$@"; }
 
-echo "==> Looking for the $TAG release"
-release="$(gh "$API/releases/tags/$TAG" 2>/dev/null || true)"
-release_id="$(printf '%s' "$release" | python3 -c 'import sys,json;print(json.load(sys.stdin).get("id",""))' 2>/dev/null || true)"
+# Anchor the tag in Gitea — see the header. **Created if absent, never moved.**
+#
+# An earlier version deleted and recreated it so the tag would name the current
+# build. That was worse than useless: nothing about the channel depends on
+# which commit the tag points at — the update string resolves the tag by *name*
+# and the assets hang off the release object — while a DELETE followed by a
+# failed POST destroys a working anchor and leaves a window in which a mirror
+# run prunes GitHub's copy. A transient Gitea error would have converted a
+# healthy channel into a dead one, which is strictly worse than this step not
+# existing. Gitea's POST /tags has no force semantics, so the DELETE was only
+# ever there to get around a 409; asking first removes the need.
+echo "==> Anchoring the $TAG tag in Gitea"
+anchor_probe="$(tea_code "$GITEA_API/repos/$GITEA_REPO/tags/$TAG")"
+case "$anchor_probe" in
+  200)
+    echo "    already anchored — left alone"
+    ;;
+  404)
+    echo "    creating it at ${GITEA_SHA:0:9}"
+    tea -X POST "$GITEA_API/repos/$GITEA_REPO/tags" \
+      -d "{\"tag_name\": \"$TAG\", \"target\": \"$GITEA_SHA\", \"message\": \"Rolling Linux update channel\"}" \
+      >/dev/null
+    ;;
+  *)
+    echo "FAILED: Gitea answered $anchor_probe asking whether the $TAG tag exists." >&2
+    echo "        Refusing to guess — creating it blindly would 409 over an" >&2
+    echo "        existing tag and abort the release." >&2
+    exit 1
+    ;;
+esac
+
+# Not best-effort. Without this tag the mirror removes GitHub's and the
+# channel dies silently somewhere between now and four hours from now. Reported
+# by code, so "Gitea was unreachable" cannot masquerade as "the tag is gone".
+anchor_code="$(tea_code "$GITEA_API/repos/$GITEA_REPO/tags/$TAG")"
+[ "$anchor_code" = "200" ] || {
+  echo "FAILED: the $TAG tag is not readable in Gitea (HTTP $anchor_code);" >&2
+  echo "        without it the mirror would delete GitHub's copy." >&2
+  exit 1
+}
+
+# Look through the authenticated list rather than /releases/tags/, which never
+# returns drafts. That matters here specifically: GitHub demotes a published
+# release to a draft when its tag is deleted, which is the state every mirror
+# run left behind, so the by-tag lookup reports "absent" while orphaned drafts
+# sit there holding 86 MB each. Reuse the newest and delete the rest, or they
+# accumulate one per release forever.
+echo "==> Looking for the $TAG release (drafts included)"
+all_releases="$(gh "$API/releases?per_page=100")"
+mapfile -t existing < <(printf '%s' "$all_releases" | python3 -c '
+import sys, json
+tag = sys.argv[1]
+rs = [r for r in json.load(sys.stdin) if r.get("tag_name") == tag]
+rs.sort(key=lambda r: r.get("created_at",""), reverse=True)
+for r in rs:
+    print(r["id"])
+' "$TAG")
+
+release_id="${existing[0]:-}"
+
+for stale in "${existing[@]:1}"; do
+  echo "    deleting orphaned duplicate release $stale"
+  gh -X DELETE "$API/releases/$stale" >/dev/null || true
+done
+
+if [ -n "$release_id" ]; then
+  # A draft has no tag and serves no download URL, so it has to be republished.
+  echo "    reusing release $release_id"
+  # `make_latest` is not optional here even though this release already exists.
+  # Publishing a draft is a publish transition, where the API's documented
+  # default is `true` — so omitting it would quietly promote this channel to
+  # the repository's "Latest release" and bury the versioned release a person
+  # actually wants from the releases page.
+  #
+  # `tag_name` is re-sent deliberately, and must be: the API removes the tag
+  # when a PATCH omits it. Given this whole change exists because a tag
+  # disappeared, that is an expensive line to tidy away.
+  gh -X PATCH "$API/releases/$release_id" \
+    -d "{\"tag_name\": \"$TAG\", \"draft\": false, \"make_latest\": \"false\"}" >/dev/null
+  release="$(gh "$API/releases/$release_id")"
+fi
 
 if [ -z "$release_id" ]; then
   echo "==> Creating it"
   # Not a prerelease, but deliberately not the "latest" release either: this
   # tag is a channel, and it must never displace the versioned release a
   # person lands on from the releases page.
-  release="$(gh -X POST "$API/releases" -d "$(python3 -c '
+  body_json="$(python3 -c '
 import json
 print(json.dumps({
     "tag_name": "'"$TAG"'",
     "name": "Linux update channel",
-    "body": "Rolling AppImage build that Triple-C’s in-app updater reads. "
+    "body": "Rolling AppImage build that Triple-C\u2019s in-app updater reads. "
             "The two files here are replaced on every release; for a specific "
             "version, use the versioned releases instead.",
     "draft": False,
     "prerelease": False,
     "make_latest": "false",
-}))')")"
+}))')"
+
+  # `already_exists` is a benign, recoverable answer, not a reason to abort the
+  # last step of build-linux and lose the release with it. It means a release
+  # for this tag exists but the listing above did not show it — a draft that has
+  # sunk past the first page, since a draft's created_at is frozen while newer
+  # releases push it down. Re-ask by tag and carry on.
+  create_body="$(mktemp)"
+  create_code="$(curl -s -o "$create_body" -w '%{http_code}' \
+    -H "Authorization: Bearer $GH_PAT" -H "Accept: application/vnd.github+json" \
+    -X POST "$API/releases" -d "$body_json")"
+
+  case "$create_code" in
+    201)
+      release="$(cat "$create_body")"
+      ;;
+    422)
+      if grep -q "already_exists" "$create_body"; then
+        echo "    a release for $TAG already exists but was not listed — reusing it"
+        release="$(gh "$API/releases/tags/$TAG")"
+      else
+        echo "FAILED: GitHub rejected the release (422):" >&2
+        cat "$create_body" >&2
+        rm -f "$create_body"
+        exit 1
+      fi
+      ;;
+    *)
+      echo "FAILED: creating the $TAG release returned $create_code:" >&2
+      cat "$create_body" >&2
+      rm -f "$create_body"
+      exit 1
+      ;;
+  esac
+  rm -f "$create_body"
+
   release_id="$(printf '%s' "$release" | python3 -c 'import sys,json;print(json.load(sys.stdin)["id"])')"
 fi
 
-echo "==> Removing superseded assets from release $release_id"
-printf '%s' "$release" | python3 -c '
+# One asset at a time, delete immediately followed by upload. Deleting both up
+# front leaves the channel holding a fresh AppImage and no .zsync if the second
+# upload fails, and a client that cannot fetch the .zsync simply stops updating
+# — no error anyone here would see.
+asset_ids="$(printf '%s' "$release" | python3 -c '
 import sys, json
 keep = set(sys.argv[1:])
+out = {}
 for a in json.load(sys.stdin).get("assets", []):
     if a["name"] in keep:
-        print(a["id"])
-' "${ASSETS[@]}" | while read -r asset_id; do
-  [ -n "$asset_id" ] || continue
-  gh -X DELETE "$API/releases/assets/$asset_id" >/dev/null || true
-done
+        out[a["name"]] = a["id"]
+print(json.dumps(out))
+' "${ASSETS[@]}")"
 
+# --retry/--max-time/--http1.1 for the reason the Gitea upload steps in this
+# repo carry them: real mid-stream failures on large assets (curl 92 and 28).
 for asset in "${ASSETS[@]}"; do
+  stale_id="$(printf '%s' "$asset_ids" | python3 -c 'import sys,json;print(json.load(sys.stdin).get(sys.argv[1],""))' "$asset")"
+  if [ -n "$stale_id" ]; then
+    echo "==> Replacing $asset (dropping superseded asset $stale_id)"
+    gh -X DELETE "$API/releases/assets/$stale_id" >/dev/null || true
+  fi
   echo "==> Uploading $asset ($(du -h "$asset" | cut -f1))"
-  curl -sf -X POST \
+  curl -sf --http1.1 --retry 5 --retry-all-errors --retry-delay 5 --max-time 900 \
+    -X POST \
     -H "Authorization: Bearer $GH_PAT" \
     -H "Content-Type: application/octet-stream" \
     --data-binary "@$asset" \
@@ -84,12 +237,22 @@ done
 # The updater is only as good as this URL, and a silent failure here means
 # every installed copy quietly stops updating. Confirm both are actually
 # fetchable at the address the AppImage was built to check.
+# Size as well as status: a 200 only proves something is served at the
+# address, not that it is this build. GitHub accepting a truncated upload
+# would pass a status-only check and then fail every client's checksum.
 echo "==> Verifying the published URLs"
 for asset in "${ASSETS[@]}"; do
   url="https://github.com/$REPO/releases/download/$TAG/$asset"
-  code="$(curl -s -o /dev/null -w '%{http_code}' -L "$url")"
-  [ "$code" = "200" ] || { echo "FAILED: $url returned $code" >&2; exit 1; }
-  echo "    $code  $url"
+  local_size="$(stat -c %s "$asset")"
+
+  headers="$(curl -sIL "$url" | tr -d '\r')"
+  code="$(printf '%s\n' "$headers" | awk '/^HTTP\//{c=$2} END{print c}')"
+  served="$(printf '%s\n' "$headers" | awk 'tolower($1)=="content-length:"{n=$2} END{print n}')"
+
+  [ "$code" = "200" ] || { echo "FAILED: $url returned ${code:-no status}" >&2; exit 1; }
+  [ "$served" = "$local_size" ] \
+    || { echo "FAILED: $url serves ${served:-unknown} bytes, built $local_size." >&2; exit 1; }
+  echo "    $code  $served bytes  $url"
 done
 
-echo "OK: $TAG updated."
+echo "OK: $TAG updated, and anchored in Gitea so the mirror preserves it."