feat(worker): surface startup recovery via OperationProgress channel

The six Lifecycle/*Recovery hosted services now broadcast one
OperationProgress("startup-recovery", <phase>, current, total) message each
after they finish, instead of leaving the UI on a bare "connecting" text
during worker startup. IslandsShellViewModel subscribes and swaps in
"Recovering... (i/n)" (existing ops.worker.startupRecovery key, no locale
changes) while Worker.IsReconnecting is true, and clears it once actually
connected so a later transient reconnect doesn't replay stale text.

OperationProgress broadcasts to Clients.All with no replay-on-connect, so a
UI that hasn't finished its SignalR handshake yet can miss some or all of
these messages and simply keep showing "connecting" as before -- accepted
rather than adding a cached-state + reconnect-replay path (mirroring
RefreshExternalMergeConflictsAsync) for what is a fast, best-effort,
local-only startup sweep with no UI-visible failure mode beyond that.

tests/ClaudeDo.Worker.Tests/Lifecycle/PromptFileRecoveryTests.cs

@@ -1,6 +1,8 @@
 using System.Text.Json;
 using ClaudeDo.Data;
+using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Lifecycle;
+using ClaudeDo.Worker.Tests.Infrastructure;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 
@@ -49,7 +51,8 @@ public sealed class PromptFileRecoveryTests
             var orphanPath = Path.Combine(root, "agent.md");
             File.WriteAllText(orphanPath, "leftover");
 
-            var sut = new PromptFileRecovery(NullLogger<PromptFileRecovery>.Instance, root);
+            var hubContext = new CapturingHubContext();
+            var sut = new PromptFileRecovery(NullLogger<PromptFileRecovery>.Instance, new HubBroadcaster(hubContext), root);
 
             await sut.StartAsync(CancellationToken.None);
 
@@ -57,6 +60,8 @@ public sealed class PromptFileRecoveryTests
             Assert.True(File.Exists(PromptFiles.PathFor(PromptKind.System, root)), "Real edit must survive");
             Assert.False(File.Exists(orphanPath), "Orphan must be moved out of the prompts root");
             Assert.True(File.Exists(Path.Combine(root, "_orphans", "agent.md")), "Orphan must be quarantined, not deleted");
+            Assert.Contains(hubContext.Proxy.Calls, c =>
+                c.Method == "OperationProgress" && (string)c.Args[0]! == "startup-recovery");
 
             await sut.StopAsync(CancellationToken.None); // must not throw
         }
@@ -77,7 +82,7 @@ public sealed class PromptFileRecoveryTests
             File.WriteAllText(orphanPath, "my old customized triage+wait+merge prompt");
 
             var logger = new CapturingLogger<PromptFileRecovery>();
-            var sut = new PromptFileRecovery(logger, root);
+            var sut = new PromptFileRecovery(logger, new HubBroadcaster(new CapturingHubContext()), root);
 
             await sut.StartAsync(CancellationToken.None);