diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index e1fa7baed..dde229900 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -737,93 +737,3 @@ jobs:
         run: |
           set -euxo pipefail
           gh release upload "$GITHUB_REF_NAME" latest.json --clobber --repo "$GITHUB_REPOSITORY"
-
-  # Mirror the release assets to Cloudflare R2 so ccswitch.io/download can
-  # serve them directly (dl.ccswitch.io). Skips itself when the R2 secrets
-  # are not configured (e.g. on forks). Required secrets:
-  #   R2_ACCOUNT_ID / R2_ACCESS_KEY_ID / R2_SECRET_ACCESS_KEY
-  sync-to-r2:
-    name: Sync release to R2
-    runs-on: ubuntu-22.04
-    needs: assemble-latest-json
-    permissions:
-      contents: read
-    env:
-      R2_BUCKET: cc-switch-releases
-      R2_PUBLIC_BASE_URL: https://dl.ccswitch.io
-      KEEP_VERSIONS: "5"
-      AWS_ACCESS_KEY_ID: ${{ secrets.R2_ACCESS_KEY_ID }}
-      AWS_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}
-      AWS_DEFAULT_REGION: auto
-      # aws-cli >= 2.23 defaults to CRC checksums that R2 rejects.
-      AWS_REQUEST_CHECKSUM_CALCULATION: when_required
-      AWS_RESPONSE_CHECKSUM_VALIDATION: when_required
-      R2_ENDPOINT: https://${{ secrets.R2_ACCOUNT_ID }}.r2.cloudflarestorage.com
-    steps:
-      - name: Check R2 secrets
-        id: r2
-        run: |
-          if [ -n "$AWS_ACCESS_KEY_ID" ]; then
-            echo "configured=true" >> "$GITHUB_OUTPUT"
-          else
-            echo "configured=false" >> "$GITHUB_OUTPUT"
-            echo "R2 secrets not configured; skipping download mirror sync."
-          fi
-
-      - name: Checkout scripts
-        if: steps.r2.outputs.configured == 'true'
-        uses: actions/checkout@v6
-        with:
-          sparse-checkout: scripts
-
-      - name: Download release assets
-        if: steps.r2.outputs.configured == 'true'
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          set -euo pipefail
-          mkdir -p r2-assets
-          gh release download "$GITHUB_REF_NAME" --dir r2-assets --repo "$GITHUB_REPOSITORY"
-          ls -la r2-assets
-
-      - name: Generate download manifest
-        if: steps.r2.outputs.configured == 'true'
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          set -euo pipefail
-          pub_date=$(gh release view "$GITHUB_REF_NAME" --repo "$GITHUB_REPOSITORY" --json publishedAt --jq .publishedAt)
-          node scripts/generate-download-manifest.mjs r2-assets "$GITHUB_REF_NAME" "$R2_PUBLIC_BASE_URL" manifest.json "$pub_date"
-
-      - name: Upload assets and manifest to R2
-        if: steps.r2.outputs.configured == 'true'
-        run: |
-          set -euo pipefail
-          # Versioned asset paths never change — cache hard at the edge.
-          aws s3 cp r2-assets "s3://$R2_BUCKET/$GITHUB_REF_NAME/" \
-            --recursive \
-            --exclude "*.sig" --exclude "*.tar.gz" --exclude "latest.json" \
-            --cache-control "public, max-age=31536000, immutable" \
-            --endpoint-url "$R2_ENDPOINT"
-          # The manifest is replaced on every release — keep edge cache short.
-          aws s3 cp manifest.json "s3://$R2_BUCKET/manifest.json" \
-            --content-type "application/json" \
-            --cache-control "public, max-age=300" \
-            --endpoint-url "$R2_ENDPOINT"
-
-      - name: Prune old versions
-        if: steps.r2.outputs.configured == 'true'
-        run: |
-          set -euo pipefail
-          versions=$(aws s3 ls "s3://$R2_BUCKET/" --endpoint-url "$R2_ENDPOINT" \
-            | awk '$1 == "PRE" {print $2}' | tr -d '/' | grep -E '^v[0-9]' | sort -V || true)
-          count=$(printf '%s\n' "$versions" | grep -c . || true)
-          if [ "$count" -le "$KEEP_VERSIONS" ]; then
-            echo "Nothing to prune ($count versions, keeping up to $KEEP_VERSIONS)."
-            exit 0
-          fi
-          printf '%s\n' "$versions" | head -n "-$KEEP_VERSIONS" | while read -r old; do
-            [ -n "$old" ] || continue
-            echo "Pruning s3://$R2_BUCKET/$old/"
-            aws s3 rm "s3://$R2_BUCKET/$old/" --recursive --endpoint-url "$R2_ENDPOINT"
-          done
diff --git a/.github/workflows/sync-r2.yml b/.github/workflows/sync-r2.yml
new file mode 100644
index 000000000..4ce61372d
--- /dev/null
+++ b/.github/workflows/sync-r2.yml
@@ -0,0 +1,222 @@
+# Mirror release assets to Cloudflare R2 so ccswitch.io/download can serve
+# them directly (dl.ccswitch.io), and mirror the Tauri updater manifest and
+# artifacts so in-app updates avoid GitHub too (the updater verifies minisign
+# signatures client-side, so the mirror is untrusted).
+#
+# Triggered on release promotion (`released` fires when a prerelease is
+# flipped to a full release, or a release is published as stable directly) —
+# NOT on tag push. This keeps the R2 root manifests behind the same gate as
+# GitHub's /releases/latest/: while a release sits as prerelease, neither the
+# download page nor the updater sees it. Additionally, a run only touches the
+# root manifests (and prunes old versions) when its tag IS releases/latest —
+# manual backfills of older tags restore versioned files only.
+#
+# Caveat (by design of tauri-plugin-updater): the updater stops at the first
+# endpoint whose response parses, so a stale-but-valid R2 manifest would mask
+# newer GitHub releases. That is why this sync hard-fails on the official
+# repo when the R2 secrets are missing, instead of silently skipping.
+#
+# Required secrets: R2_ACCOUNT_ID / R2_ACCESS_KEY_ID / R2_SECRET_ACCESS_KEY
+name: Sync release to R2
+
+on:
+  release:
+    types: [released]
+  # Manual recovery/backfill: re-sync any existing release tag.
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Release tag to sync (e.g. v3.18.0)'
+        required: true
+        type: string
+
+permissions:
+  contents: read
+
+# latest.json / manifest.json are last-writer-wins — serialize runs and keep
+# every trigger queued instead of the default replace-the-pending behavior.
+concurrency:
+  group: sync-r2
+  cancel-in-progress: false
+  queue: max
+
+jobs:
+  sync-to-r2:
+    name: Sync release to R2
+    runs-on: ubuntu-22.04
+    env:
+      R2_BUCKET: cc-switch-releases
+      R2_PUBLIC_BASE_URL: https://dl.ccswitch.io
+      KEEP_VERSIONS: "5"
+      AWS_ACCESS_KEY_ID: ${{ secrets.R2_ACCESS_KEY_ID }}
+      AWS_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}
+      AWS_DEFAULT_REGION: auto
+      # aws-cli >= 2.23 defaults to CRC checksums that R2 rejects.
+      AWS_REQUEST_CHECKSUM_CALCULATION: when_required
+      AWS_RESPONSE_CHECKSUM_VALIDATION: when_required
+      R2_ENDPOINT: https://${{ secrets.R2_ACCOUNT_ID }}.r2.cloudflarestorage.com
+      TAG: ${{ github.event.release.tag_name || inputs.tag }}
+    steps:
+      - name: Check R2 secrets
+        id: r2
+        env:
+          R2_ACCOUNT_ID: ${{ secrets.R2_ACCOUNT_ID }}
+        run: |
+          if [ -z "$TAG" ]; then
+            echo "::error::No release tag to sync."
+            exit 1
+          fi
+          if [ -n "$R2_ACCOUNT_ID" ] && [ -n "$AWS_ACCESS_KEY_ID" ] && [ -n "$AWS_SECRET_ACCESS_KEY" ]; then
+            echo "configured=true" >> "$GITHUB_OUTPUT"
+          elif [ "$GITHUB_REPOSITORY" = "farion1231/cc-switch" ]; then
+            # A silently stale mirror strands updater users on old versions
+            # (the R2 endpoint wins as long as its manifest parses), so the
+            # official repo must never skip this sync.
+            echo "::error::R2 secrets (R2_ACCOUNT_ID / R2_ACCESS_KEY_ID / R2_SECRET_ACCESS_KEY) are missing on the official repo; refusing to skip the mirror sync."
+            exit 1
+          else
+            echo "configured=false" >> "$GITHUB_OUTPUT"
+            echo "R2 secrets not configured; skipping download mirror sync."
+          fi
+
+      # Only the tag that IS GitHub's releases/latest may touch the bucket-root
+      # manifests or prune old versions. This keeps manual backfills of old
+      # tags harmless (they only restore versioned files — otherwise the root
+      # manifests would point at a version the prune step deletes right after)
+      # and makes out-of-order runs self-correcting: whichever run executes,
+      # only the true latest publishes the manifests.
+      - name: Check whether tag is the latest stable release
+        id: latest
+        if: steps.r2.outputs.configured == 'true'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          # An API failure must fail the run — mapping it to "not latest"
+          # would skip the root manifests on a green run, silently leaving
+          # them stale (the exact failure mode this workflow exists to make
+          # loud). Retry transient errors, then give up loudly.
+          latest=""
+          for attempt in 1 2 3 4; do
+            latest=$(gh api "repos/$GITHUB_REPOSITORY/releases/latest" --jq .tag_name || true)
+            if [ -n "$latest" ]; then
+              break
+            fi
+            if [ "$attempt" -lt 4 ]; then
+              sleep $((attempt * 10))
+            fi
+          done
+          if [ -z "$latest" ]; then
+            echo "::error::Could not resolve the latest stable release from GitHub after 4 attempts; failing instead of guessing."
+            exit 1
+          fi
+          if [ "$TAG" = "$latest" ]; then
+            echo "is_latest=true" >> "$GITHUB_OUTPUT"
+            echo "$TAG is the latest stable release; full sync."
+          else
+            echo "is_latest=false" >> "$GITHUB_OUTPUT"
+            echo "::warning::$TAG is not the latest stable release ($latest); syncing versioned files only — root manifests and pruning are skipped."
+          fi
+
+      - name: Checkout scripts
+        if: steps.r2.outputs.configured == 'true' && steps.latest.outputs.is_latest == 'true'
+        uses: actions/checkout@v6
+        with:
+          sparse-checkout: scripts
+
+      - name: Download release assets
+        if: steps.r2.outputs.configured == 'true'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          mkdir -p r2-assets
+          gh release download "$TAG" --dir r2-assets --repo "$GITHUB_REPOSITORY"
+          ls -la r2-assets
+
+      - name: Generate download manifest
+        if: steps.r2.outputs.configured == 'true' && steps.latest.outputs.is_latest == 'true'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          pub_date=$(gh release view "$TAG" --repo "$GITHUB_REPOSITORY" --json publishedAt --jq .publishedAt)
+          node scripts/generate-download-manifest.mjs r2-assets "$TAG" "$R2_PUBLIC_BASE_URL" manifest.json "$pub_date"
+
+      - name: Rewrite updater manifest for R2
+        if: steps.r2.outputs.configured == 'true' && steps.latest.outputs.is_latest == 'true'
+        run: |
+          set -euo pipefail
+          node scripts/rewrite-updater-manifest.mjs r2-assets/latest.json "$TAG" "$R2_PUBLIC_BASE_URL" latest-r2.json
+
+      - name: Upload versioned assets to R2
+        if: steps.r2.outputs.configured == 'true'
+        run: |
+          set -euo pipefail
+          # Versioned asset paths never change — cache hard at the edge.
+          # .tar.gz is the macOS updater payload; .sig files are not needed
+          # (signatures are embedded in latest.json) and latest.json goes to
+          # the bucket root with a short TTL instead.
+          aws s3 cp r2-assets "s3://$R2_BUCKET/$TAG/" \
+            --recursive \
+            --exclude "*.sig" --exclude "latest.json" \
+            --cache-control "public, max-age=31536000, immutable" \
+            --endpoint-url "$R2_ENDPOINT"
+
+      - name: Publish root manifests to R2
+        if: steps.r2.outputs.configured == 'true' && steps.latest.outputs.is_latest == 'true'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          # Re-verify right before touching the root manifests: a newer
+          # release may have been promoted while assets were downloading.
+          # Skipping then is safe — the newer release's own queued run
+          # publishes the newer manifests. An unresolvable API is still a
+          # hard failure, never a guess.
+          latest=""
+          for attempt in 1 2 3 4; do
+            latest=$(gh api "repos/$GITHUB_REPOSITORY/releases/latest" --jq .tag_name || true)
+            if [ -n "$latest" ]; then
+              break
+            fi
+            if [ "$attempt" -lt 4 ]; then
+              sleep $((attempt * 10))
+            fi
+          done
+          if [ -z "$latest" ]; then
+            echo "::error::Could not re-verify the latest stable release before publishing root manifests; failing instead of guessing."
+            exit 1
+          fi
+          if [ "$TAG" != "$latest" ]; then
+            echo "::warning::$TAG stopped being the latest stable release mid-run ($latest is); leaving root manifests untouched."
+            exit 0
+          fi
+          # Both manifests are replaced on every release — keep edge cache
+          # short. Uploaded after the assets they reference so an aborted run
+          # never leaves them pointing at missing files.
+          aws s3 cp manifest.json "s3://$R2_BUCKET/manifest.json" \
+            --content-type "application/json" \
+            --cache-control "public, max-age=300" \
+            --endpoint-url "$R2_ENDPOINT"
+          aws s3 cp latest-r2.json "s3://$R2_BUCKET/latest.json" \
+            --content-type "application/json" \
+            --cache-control "public, max-age=300" \
+            --endpoint-url "$R2_ENDPOINT"
+
+      - name: Prune old versions
+        if: steps.r2.outputs.configured == 'true' && steps.latest.outputs.is_latest == 'true'
+        run: |
+          set -euo pipefail
+          versions=$(aws s3 ls "s3://$R2_BUCKET/" --endpoint-url "$R2_ENDPOINT" \
+            | awk '$1 == "PRE" {print $2}' | tr -d '/' | grep -E '^v[0-9]' | sort -V || true)
+          count=$(printf '%s\n' "$versions" | grep -c . || true)
+          if [ "$count" -le "$KEEP_VERSIONS" ]; then
+            echo "Nothing to prune ($count versions, keeping up to $KEEP_VERSIONS)."
+            exit 0
+          fi
+          printf '%s\n' "$versions" | head -n "-$KEEP_VERSIONS" | while read -r old; do
+            [ -n "$old" ] || continue
+            echo "Pruning s3://$R2_BUCKET/$old/"
+            aws s3 rm "s3://$R2_BUCKET/$old/" --recursive --endpoint-url "$R2_ENDPOINT"
+          done
diff --git a/scripts/rewrite-updater-manifest.mjs b/scripts/rewrite-updater-manifest.mjs
new file mode 100644
index 000000000..e53e9fb23
--- /dev/null
+++ b/scripts/rewrite-updater-manifest.mjs
@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+// Rewrites the Tauri updater manifest (latest.json) so its download URLs point
+// at the R2 mirror instead of GitHub Releases. Minisign signatures cover file
+// contents, not URLs, so they stay valid unchanged — the updater still verifies
+// every downloaded artifact against the pubkey baked into the app.
+//
+// Usage: node scripts/rewrite-updater-manifest.mjs <latest-json> <tag> <base-url> [output]
+
+import { readFileSync, writeFileSync } from 'node:fs';
+
+const [input, tag, baseUrl, output = 'latest-r2.json'] = process.argv.slice(2);
+
+if (!input || !tag || !baseUrl) {
+  console.error('Usage: node scripts/rewrite-updater-manifest.mjs <latest-json> <tag> <base-url> [output]');
+  process.exit(1);
+}
+
+const manifest = JSON.parse(readFileSync(input, 'utf8'));
+const platforms = Object.entries(manifest.platforms ?? {});
+if (platforms.length === 0) {
+  console.error(`No platforms found in ${input}`);
+  process.exit(1);
+}
+
+const normalizedBase = baseUrl.replace(/\/+$/, '');
+// Mirrored artifacts live at <base>/<tag>/<file>; on GitHub they live at
+// .../releases/download/<tag>/<file>. Rebuild from the filename rather than
+// prefix-replacing so a layout change on either side fails loudly here.
+const githubPrefix = `https://github.com/`;
+
+for (const [key, entry] of platforms) {
+  if (typeof entry?.url !== 'string' || typeof entry?.signature !== 'string') {
+    console.error(`Platform ${key} is missing url or signature`);
+    process.exit(1);
+  }
+  if (!entry.url.startsWith(githubPrefix) || !entry.url.includes(`/releases/download/${tag}/`)) {
+    console.error(`Platform ${key} has unexpected url for ${tag}: ${entry.url}`);
+    process.exit(1);
+  }
+  const name = entry.url.split('/').pop();
+  entry.url = `${normalizedBase}/${tag}/${name}`;
+}
+
+writeFileSync(output, `${JSON.stringify(manifest, null, 2)}\n`);
+console.log(`Wrote ${output} with ${platforms.length} platforms pointing at ${normalizedBase}/${tag}/`);
diff --git a/src-tauri/tauri.conf.json b/src-tauri/tauri.conf.json
index 322008ac6..c93d55b25 100644
--- a/src-tauri/tauri.conf.json
+++ b/src-tauri/tauri.conf.json
@@ -62,6 +62,7 @@
     "updater": {
       "pubkey": "dW50cnVzdGVkIGNvbW1lbnQ6IG1pbmlzaWduIHB1YmxpYyBrZXk6IEM4MDI4QzlBNTczOTI4RTMKUldUaktEbFhtb3dDeUM5US9kT0FmdGR5Ti9vQzcwa2dTMlpibDVDUmQ2M0VGTzVOWnd0SGpFVlEK",
       "endpoints": [
+        "https://dl.ccswitch.io/latest.json",
         "https://github.com/farion1231/cc-switch/releases/latest/download/latest.json"
       ]
     }