Cut over the window to Explorer.Host.exe so only the host writes the index.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/Explorer.Application/SourceManager.cs

@@ -1,4 +1,5 @@
 using System.Diagnostics;
+using Explorer.Contracts;
 using Explorer.Domain;
 using Explorer.Domain.Abstractions;
 using Microsoft.Extensions.Logging;
@@ -12,6 +13,7 @@ public sealed class SourceManager
     private readonly IAppEnvironment _env;
     private readonly IClock _clock;
     private readonly ILogger<SourceManager> _logger;
+    private readonly ISourceHost? _remote;
 
     private readonly object _refreshLock = new();
     private Task<IReadOnlyList<Source>>? _refreshInFlight;
@@ -23,18 +25,31 @@ public sealed class SourceManager
         IVolumeService volumes,
         IAppEnvironment env,
         IClock clock,
-        ILogger<SourceManager> logger)
+        ILogger<SourceManager> logger,
+        ISourceHost? remote = null)
     {
         _store = store;
         _volumes = volumes;
         _env = env;
         _clock = clock;
         _logger = logger;
+        _remote = remote;
     }
 
     public async Task InitializeAsync(CancellationToken cancellationToken = default)
     {
         await _store.OpenAsync(cancellationToken).ConfigureAwait(false);
+        if (!_store.CanWrite)
+        {
+            if (_remote is not null)
+            {
+                await _remote.RefreshAsync(cancellationToken).ConfigureAwait(false);
+            }
+
+            InvalidateRefreshCache();
+            return;
+        }
+
         await _store.ScanJobs.InterruptRunningAsync(cancellationToken).ConfigureAwait(false);
         await _store.Excludes.EnsureDefaultsAsync(DefaultExcludes.Create(), cancellationToken).ConfigureAwait(false);
         await RefreshOnlineStateAsync(cancellationToken).ConfigureAwait(false);
@@ -70,6 +85,22 @@ public sealed class SourceManager
 
     private async Task<IReadOnlyList<Source>> RefreshOnlineStateCoreAsync(CancellationToken cancellationToken)
     {
+        if (!_store.CanWrite)
+        {
+            if (_remote is not null)
+            {
+                await _remote.RefreshAsync(cancellationToken).ConfigureAwait(false);
+            }
+
+            var snapshot = await _store.Sources.GetAllAsync(cancellationToken).ConfigureAwait(false);
+            lock (_refreshLock)
+            {
+                _refreshCacheTimestamp = Stopwatch.GetTimestamp();
+            }
+
+            return snapshot;
+        }
+
         var started = Stopwatch.GetTimestamp();
         var known = (await _store.Sources.GetAllAsync(cancellationToken).ConfigureAwait(false)).ToList();
         var online = _volumes.EnumerateOnlineVolumes();
@@ -201,6 +232,18 @@ public sealed class SourceManager
 
     public async Task<Source> AddUncAsync(string path, CancellationToken cancellationToken = default)
     {
+        if (!_store.CanWrite)
+        {
+            if (_remote is null)
+            {
+                throw new InvalidOperationException("Cannot add a network location while the index is read-only.");
+            }
+
+            var added = await _remote.AddUncAsync(path, cancellationToken).ConfigureAwait(false);
+            InvalidateRefreshCache();
+            return added;
+        }
+
         var root = PathRules.CanonicalUncRoot(path);
         var known = await _store.Sources.GetAllAsync(cancellationToken).ConfigureAwait(false);
         var fp = new VolumeFingerprint
@@ -269,6 +312,18 @@ public sealed class SourceManager
 
     public async Task<bool> ForgetDisconnectedAsync(string path, CancellationToken cancellationToken = default)
     {
+        if (!_store.CanWrite)
+        {
+            if (_remote is null)
+            {
+                return false;
+            }
+
+            var forgotten = await _remote.ForgetAsync(path, cancellationToken).ConfigureAwait(false);
+            InvalidateRefreshCache();
+            return forgotten;
+        }
+
         var source = await FindSourceRootAsync(path, cancellationToken).ConfigureAwait(false);
         if (source is null || !CanForget(source))
         {
@@ -324,6 +379,18 @@ public sealed class SourceManager
             return null;
         }
 
+        if (!_store.CanWrite)
+        {
+            if (_remote is null)
+            {
+                return await FindByPathAsync(path, cancellationToken).ConfigureAwait(false);
+            }
+
+            var ensured = await _remote.EnsureForPathAsync(path, cancellationToken).ConfigureAwait(false);
+            InvalidateRefreshCache();
+            return ensured;
+        }
+
         var existing = await FindByPathAsync(path, cancellationToken).ConfigureAwait(false);
         if (existing is not null)
         {