diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 18b70e21..89477eba 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1670,6 +1670,18 @@ jobs:
             grep -q 'sparkle:edSignature' "${f}" || { echo "❌ ${f} has no EdDSA signature"; exit 1; }
           done
 
+          # Channel policy: RC users update to the next RC OR the next stable,
+          # whichever is newer; stable users only ever see stables. A stable
+          # release therefore also refreshes the BETA feeds with its (untagged,
+          # visible-to-every-channel) item — otherwise RC users would sit on
+          # their last RC forever once the cycle ends. SemVer precedence in the
+          # tray orders X.Y.Z above X.Y.Z-rc.N, so the stable always wins.
+          for ARCH in arm64 amd64; do
+            if [ -f "appcast-out/appcast-${ARCH}.xml" ]; then
+              cp "appcast-out/appcast-${ARCH}.xml" "appcast-out/appcast-beta-${ARCH}.xml"
+            fi
+          done
+
           gh release upload "${GITHUB_REF_NAME}" appcast-out/*.xml --clobber
           echo "generated=true" >> "$GITHUB_OUTPUT"
 
@@ -1695,6 +1707,18 @@ jobs:
           event-type: publish-appcast
           client-payload: '{"version": "${{ github.ref_name }}", "channel": "stable"}'
 
+      # Second dispatch: the same stable release also refreshes the beta feeds
+      # (see the channel-policy comment above).
+      - name: Publish stable item to the beta feeds
+        if: steps.appcast.outputs.generated == 'true'
+        continue-on-error: true
+        uses: peter-evans/repository-dispatch@28959ce8df70de7be546dd1250a005dd32156697  # v4.0.1
+        with:
+          token: ${{ secrets.MARKETING_SITE_DISPATCH_TOKEN }}
+          repository: smart-mcp-proxy/mcpproxy.app-website
+          event-type: publish-appcast
+          client-payload: '{"version": "${{ github.ref_name }}", "channel": "beta"}'
+
   provenance:
     needs: [release]
     permissions:
diff --git a/native/macos/MCPProxy/MCPProxy/Core/CoreSupersede.swift b/native/macos/MCPProxy/MCPProxy/Core/CoreSupersede.swift
index 1a0a7732..549bd758 100644
--- a/native/macos/MCPProxy/MCPProxy/Core/CoreSupersede.swift
+++ b/native/macos/MCPProxy/MCPProxy/Core/CoreSupersede.swift
@@ -82,7 +82,11 @@ struct StaleCorePrompt: Equatable {
     let pid: Int32?
 
     var menuTitle: String {
-        "Old core v\(runningVersion) running — Restart into v\(bundledVersion)"
+        // Core versions already carry their "v" prefix ("v0.54.0-rc.2");
+        // strip before re-prefixing or the label reads "vv0.54.0-rc.2".
+        let running = runningVersion.hasPrefix("v") ? String(runningVersion.dropFirst()) : runningVersion
+        let bundled = bundledVersion.hasPrefix("v") ? String(bundledVersion.dropFirst()) : bundledVersion
+        return "Old core v\(running) running — Restart into v\(bundled)"
     }
 }
 
diff --git a/native/macos/MCPProxy/MCPProxy/Services/FeedUpdater.swift b/native/macos/MCPProxy/MCPProxy/Services/FeedUpdater.swift
index b6ff4aec..141581fb 100644
--- a/native/macos/MCPProxy/MCPProxy/Services/FeedUpdater.swift
+++ b/native/macos/MCPProxy/MCPProxy/Services/FeedUpdater.swift
@@ -249,14 +249,44 @@ extension SparkleFeedUpdater: SPUUpdaterDelegate {
         let resolved = SparkleFeedURL.archSpecific(
             configured, arch: UpdateService.hostArchToken(), channel: policy.channel
         )
+        NSLog("[MCPProxy] Sparkle check: channel=%@ feed=%@",
+              policy.channel.rawValue, resolved == configured ? "(Info.plist default)" : resolved)
         return resolved == configured ? nil : resolved
     }
 
+    /// Diagnostic seam: one line per loaded appcast saying what Sparkle SAW.
+    /// Without it, "no update" is indistinguishable from "wrong feed",
+    /// "filtered channel", and "version comparison surprise" — which cost a
+    /// live debugging session on the v0.54.0-rc.3 rehearsal.
+    func updater(_ updater: SPUUpdater, didFinishLoading appcast: SUAppcast) {
+        let items = appcast.items.map { item in
+            "\(item.displayVersionString)(v=\(item.versionString),ch=\(item.channel ?? "default"))"
+        }.joined(separator: ", ")
+        NSLog("[MCPProxy] Sparkle loaded appcast: %d item(s): %@", appcast.items.count, items)
+    }
+
     /// FR-014: stable users must never be offered RCs. An empty set means
     /// "default channel only", which is exactly the stable feed; RC users also
     /// accept the `beta` channel the prerelease pipeline tags.
     func allowedChannels(for updater: SPUUpdater) -> Set<String> {
-        policy.channel.allowedSparkleChannels
+        let allowed = policy.channel.allowedSparkleChannels
+        NSLog("[MCPProxy] Sparkle allowedChannels consulted: channel=%@ -> %@",
+              policy.channel.rawValue, allowed.isEmpty ? "(default only)" : allowed.sorted().joined(separator: ","))
+        return allowed
+    }
+
+    /// FR-006 — Sparkle MUST compare versions by SemVer 2.0 precedence.
+    ///
+    /// `SUStandardVersionComparator` treats the whole prerelease suffix as
+    /// noise: it reports 0.54.0-rc.2, 0.54.0-rc.3 AND plain 0.54.0 as EQUAL
+    /// (verified against Sparkle 2.9.3 directly). Every RC→RC and RC→stable
+    /// update is therefore invisible to it — "You're up to date" on a feed
+    /// that plainly carries a newer item, found live on the v0.54.0-rc.3
+    /// dress rehearsal. The shared SemanticVersion util already implements
+    /// the correct precedence (rc.2 < rc.3 < stable); this delegate is the
+    /// missing plumbing that hands it to Sparkle.
+    func versionComparator(for updater: SPUUpdater) -> SUVersionComparison? {
+        SemVerSparkleComparator.shared
     }
 
     func updater(_ updater: SPUUpdater, didFindValidUpdate item: SUAppcastItem) {
@@ -406,4 +436,23 @@ extension SparkleFeedUpdater: SPUStandardUserDriverDelegate {
     }
 }
 
+/// SUVersionComparison backed by the shared SemVer 2.0 util (FR-006).
+///
+/// Malformed versions fall back to Sparkle's own comparator rather than
+/// guessing: `SemanticVersion.compare` returns nil for anything that is not a
+/// version, and a fabricated "equal" there is precisely the bug this class
+/// exists to fix.
+final class SemVerSparkleComparator: NSObject, SUVersionComparison {
+    static let shared = SemVerSparkleComparator()
+
+    func compareVersion(_ versionA: String, toVersion versionB: String) -> ComparisonResult {
+        if let cmp = SemanticVersion.compare(versionA, versionB) {
+            return cmp < 0 ? .orderedAscending : cmp > 0 ? .orderedDescending : .orderedSame
+        }
+        NSLog("[MCPProxy] Sparkle version compare fell back to the standard comparator: %@ vs %@",
+              versionA, versionB)
+        return SUStandardVersionComparator.default.compareVersion(versionA, toVersion: versionB)
+    }
+}
+
 #endif
diff --git a/native/macos/MCPProxy/MCPProxyTests/SemanticVersionTests.swift b/native/macos/MCPProxy/MCPProxyTests/SemanticVersionTests.swift
index 1a543633..e63e195e 100644
--- a/native/macos/MCPProxy/MCPProxyTests/SemanticVersionTests.swift
+++ b/native/macos/MCPProxy/MCPProxyTests/SemanticVersionTests.swift
@@ -175,3 +175,33 @@ final class SemanticVersionTests: XCTestCase {
         XCTAssertFalse(SemanticVersion.parse("0.54.0")!.isPrerelease)
     }
 }
+
+// MARK: - Sparkle bridge (FR-006)
+
+/// SUStandardVersionComparator reports 0.54.0-rc.2, 0.54.0-rc.3 and 0.54.0 as
+/// EQUAL — which made every RC→RC and RC→stable update invisible ("You're up
+/// to date", live on the v0.54.0-rc.3 rehearsal). These pin the bridge that
+/// hands Sparkle the SemVer comparator instead.
+final class SemVerSparkleComparatorTests: XCTestCase {
+    private let comparator = SemVerSparkleComparator.shared
+
+    func testRcToNextRcIsAnUpdate() {
+        XCTAssertEqual(comparator.compareVersion("0.54.0-rc.2", toVersion: "0.54.0-rc.3"), .orderedAscending)
+    }
+
+    func testRcToStableIsAnUpdate() {
+        XCTAssertEqual(comparator.compareVersion("0.54.0-rc.3", toVersion: "0.54.0"), .orderedAscending)
+    }
+
+    func testStableNeverDowngradesToRc() {
+        XCTAssertEqual(comparator.compareVersion("0.54.0", toVersion: "0.54.0-rc.9"), .orderedDescending)
+    }
+
+    func testNumericPrereleaseIdentifiersCompareNumerically() {
+        XCTAssertEqual(comparator.compareVersion("0.54.0-rc.2", toVersion: "0.54.0-rc.10"), .orderedAscending)
+    }
+
+    func testEqualVersionsAreEqual() {
+        XCTAssertEqual(comparator.compareVersion("0.54.0-rc.2", toVersion: "0.54.0-rc.2"), .orderedSame)
+    }
+}