agent: unify listening and dialing with directed mutual measurements

Replace Probe with Agent across node runtime, Fleet contracts, backend state, API and storage. Report incoming sessions and outgoing link health through each Agent uplink, and retain directed link controls and retry.

Update protocol fixtures and end-to-end coverage for the unified model; accept requested cancellation during the Fleet timeout test cleanup.

backend/src/MoShiro.Backend.Storage.Sqlite/SqliteConfigStores.cs

@@ -47,44 +47,6 @@ public sealed class SqliteJoinTokenStore : IJoinTokenStore
         _db.WriteAsync(c => c.Exec("DELETE FROM join_tokens WHERE id = @id", ("@id", id)) == 1, ct);
 }
 
-public sealed class SqliteProbeStore : IProbeStore
-{
-    private readonly SqliteDatabase _db;
-
-    public SqliteProbeStore(SqliteDatabase db)
-    {
-        _db = db;
-    }
-
-    public ValueTask<IReadOnlyList<ProbeRecord>> ListAsync(CancellationToken ct) =>
-        _db.ReadAsync<IReadOnlyList<ProbeRecord>>(
-            c => c.Query("SELECT id, name, pubkey, created_at, revoked_at, ipv6_diagnostics, peer_pubkey, added_by FROM probes ORDER BY created_at, id", r => new ProbeRecord(r.GetString(0), r.GetString(1), r.Bytes(2), r.GetInt64(3), r.NullableLong(4), r.NullableString(5), r.NullableBytes(6), r.NullableString(7))),
-            ct);
-
-    public ValueTask<ProbeRecord?> GetAsync(string id, CancellationToken ct) =>
-        _db.ReadAsync(
-            c => c.QueryOne("SELECT id, name, pubkey, created_at, revoked_at, ipv6_diagnostics, peer_pubkey, added_by FROM probes WHERE id = @id", r => new ProbeRecord(r.GetString(0), r.GetString(1), r.Bytes(2), r.GetInt64(3), r.NullableLong(4), r.NullableString(5), r.NullableBytes(6), r.NullableString(7)), ("@id", id)),
-            ct);
-
-    public ValueTask SetIpv6DiagnosticsAsync(string id, string diagnosticsJson, CancellationToken ct) =>
-        _db.ExecuteAsync(c => c.Exec("UPDATE probes SET ipv6_diagnostics = @diag WHERE id = @id", ("@diag", diagnosticsJson), ("@id", id)), ct);
-
-    public ValueTask<bool> RevokeAsync(string id, long nowMs, CancellationToken ct) =>
-        _db.WriteAsync(c => c.Exec("UPDATE probes SET revoked_at = @now WHERE id = @id AND revoked_at IS NULL", ("@id", id), ("@now", nowMs)) == 1, ct);
-
-    public ValueTask<bool> DeleteAsync(string id, CancellationToken ct) =>
-        _db.WriteAsync(c => c.Exec("DELETE FROM probes WHERE id = @id", ("@id", id)) == 1, ct);
-
-    public ValueTask SaveAsync(ProbeRecord probe, CancellationToken ct) =>
-        _db.ExecuteAsync(c =>
-        {
-            c.Exec(
-                "INSERT INTO probes (id, name, pubkey, peer_pubkey, created_at, revoked_at) VALUES (@id, @name, @pubkey, @peer, @at, @revoked) " +
-                "ON CONFLICT(id) DO UPDATE SET name = excluded.name, pubkey = excluded.pubkey, peer_pubkey = excluded.peer_pubkey, created_at = excluded.created_at, revoked_at = excluded.revoked_at",
-                ("@id", probe.Id), ("@name", probe.Name), ("@pubkey", probe.PublicKey), ("@peer", probe.PeerPublicKey), ("@at", probe.CreatedAtMs), ("@revoked", probe.RevokedAtMs));
-        }, ct);
-}
-
 public sealed class SqliteSettingsStore : ISettingsStore
 {
     private readonly SqliteDatabase _db;