Merge branch 'main' into claude/host-management-ui-plan-7f20ab

Seven files needed a hand. Most were two branches adding something in the same
place, but three were one branch changing what the other had moved or renamed,
and those are the ones worth reading.

The shell keeps both new fields and both constructor lines: the connection
recorder this branch built and the teams view model main did. Where main put a
teams load inside OnScreenChanged, it now sits beside the logs refresh rather
than inside RaiseSurfaceState — this branch extracted that notification block
and it is called from two properties, so a screen-specific side effect in there
would fire on every terminal switch as well.

Main gave four row types a vault id and a vault name, and this branch had moved
one of them — KnownHostRowViewModel — into its own file when the pinned keys
became a screen. Git resolved that as "deleted here, modified there" and took
the delete, which compiles as long as nobody looks: the moved copy still had
the two-argument constructor and the call site had grown to four. Carried over
by hand, along with the ordering the pins list now does on them.

The status line's quiet rule was the subtle one. Main extracted it into
IsWorthReporting; this branch had changed the same condition to read item
counts rather than raw ones, because every user action queues a log entry a
moment later and this machine reads its own entries back on the next pull. Take
main's structure and the merge builds, passes, and silently restores a bug this
branch existed partly to fix — every save's message overwritten a second after
it appears. The method now reads PulledItems and PushedItems, with the reason
in its remarks.

Two conflicts were prose that had gone stale rather than code. The keychain
screen's comment said team vaults are refused by the server's access service,
which was true when it was written and is not now; main's replacement stands,
in this branch's vocabulary. The design-gaps row for groups was claimed by both
— real host groups here, per-vault headings there — and they are different
things, so both rows stay and the difference is stated: a group is a shelf the
user chose, a vault is who can read the item.

One defect the tests found and the compiler could not. Generating a key opens
the same editor as pasting one, but not through NewKey — so it never set the
target vault main added, and a generated key was filed into whatever vault was
edited last, or none. Both key-generation tests failed on it. Fixed where the
editor opens, with the reason recorded there.

One gap is left deliberately and is written down rather than half-built. Hosts,
keys, credentials and pins are read across every vault this session holds a key
for; groups are read from the active vault alone, so a host a teammate filed
shows under UNGROUPED. Nothing is lost or misfiled — it is what the sidebar
already shows for a group that has been deleted — but closing it needs a vault
id on every group row for rename and delete, and a way to tell two vaults'
identically-named groups apart under a layout with one heading per group. Both
are worth doing and neither is a merge's business. It is in the remarks on
ReloadGroupsAsync and in docs/design-import-gaps.md.

dotnet build, dotnet test and dotnet format --verify-no-changes are all clean:
1282 tests, including the end-to-end suite against real containers.

src/DodoSSH.Client.Sync/VaultKeyring.cs

@@ -84,6 +84,93 @@ public sealed class VaultKeyring : IDisposable
         }
     }
 
+    /// <summary>
+    /// Takes a vault key this session has just generated.
+    /// </summary>
+    /// <param name="vaultId">The vault.</param>
+    /// <param name="vaultKey">
+    /// The plaintext key. <b>The keyring takes ownership</b> and zeroes it on disposal; the caller must
+    /// not keep a reference or zero it itself.
+    /// </param>
+    /// <param name="keyGeneration">The generation this key is for.</param>
+    /// <remarks>
+    /// Creating a team vault is the only case: the client generates the key, wraps it to itself and
+    /// sends the wrap, so the plaintext is already here and unwrapping the server's copy back would be
+    /// a round trip to learn something this process just chose. Adopting it also means the new vault is
+    /// usable immediately rather than at the next unlock, which is what somebody who just pressed
+    /// "create" expects.
+    /// </remarks>
+    public void Adopt(Guid vaultId, byte[] vaultKey, uint keyGeneration)
+    {
+        ObjectDisposedException.ThrowIf(disposed, this);
+        ArgumentNullException.ThrowIfNull(vaultKey);
+
+        if (keys.TryGetValue(vaultId, out var previous))
+        {
+            CryptographicOperations.ZeroMemory(previous);
+        }
+
+        keys[vaultId] = vaultKey;
+        generations[vaultId] = keyGeneration;
+
+        Unopened = [.. Unopened.Where(id => id != vaultId)];
+    }
+
+    /// <summary>
+    /// Tries to open a vault that has become readable since the session was unlocked.
+    /// </summary>
+    /// <returns>Whether the grant opened.</returns>
+    /// <remarks>
+    /// What a share looks like from the receiving end: the vault was in the list all along, listed and
+    /// unreadable, and a member holding Share has now wrapped its key. Re-opening it here rather than
+    /// waiting for a relock is the difference between "someone shared a vault with you" arriving and
+    /// arriving tomorrow.
+    /// </remarks>
+    public bool TryAdmit(UserSecretBundle bundle, StoredVault vault)
+    {
+        ObjectDisposedException.ThrowIf(disposed, this);
+        ArgumentNullException.ThrowIfNull(bundle);
+        ArgumentNullException.ThrowIfNull(vault);
+
+        if (vault.WrappedVaultKey is null)
+        {
+            return false;
+        }
+
+        if (keys.ContainsKey(vault.VaultId) && generations[vault.VaultId] == vault.KeyGeneration)
+        {
+            return true;
+        }
+
+        var key = VaultKeys.TryUnwrap(
+            bundle.EncryptionKey, vault.WrappedVaultKey, vault.VaultId, vault.KeyGeneration);
+
+        if (key is null)
+        {
+            return false;
+        }
+
+        Adopt(vault.VaultId, key, vault.KeyGeneration);
+
+        return true;
+    }
+
+    /// <summary>Records that a vault cannot be read, so the interface can say so.</summary>
+    /// <remarks>
+    /// The counterpart of <see cref="TryAdmit"/> for the case where the grant did not open. Kept
+    /// explicit rather than inferred from the absence of a key, because "no key" is also what a vault
+    /// this session has never heard of looks like.
+    /// </remarks>
+    public void MarkUnreadable(Guid vaultId)
+    {
+        ObjectDisposedException.ThrowIf(disposed, this);
+
+        if (!Unopened.Contains(vaultId))
+        {
+            Unopened = [.. Unopened, vaultId];
+        }
+    }
+
     /// <summary>
     /// Borrows a vault's key.
     /// </summary>