fix: align backend APIs and upload flow

GroupService.Infrastructure/Migrations/20260909000200_ApiAlignmentFixes.cs

@@ -0,0 +1,48 @@
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+namespace GroupService.Infrastructure.Migrations
+{
+    [DbContext(typeof(GroupDbContext))]
+    [Migration("20260909000200_ApiAlignmentFixes")]
+    public partial class ApiAlignmentFixes : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_group_members_UserId_IsDeleted_GroupId",
+                table: "group_members",
+                columns: new[] { "UserId", "IsDeleted", "GroupId" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_group_members_GroupId_IsDeleted_Role",
+                table: "group_members",
+                columns: new[] { "GroupId", "IsDeleted", "Role" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_group_join_requests_Id",
+                table: "group_join_requests",
+                column: "Id",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_group_join_requests_GroupId_State_CreationTime",
+                table: "group_join_requests",
+                columns: new[] { "GroupId", "State", "CreationTime" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_group_join_requests_UserId_CreationTime",
+                table: "group_join_requests",
+                columns: new[] { "UserId", "CreationTime" });
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex("IX_group_members_UserId_IsDeleted_GroupId", "group_members");
+            migrationBuilder.DropIndex("IX_group_members_GroupId_IsDeleted_Role", "group_members");
+            migrationBuilder.DropIndex("IX_group_join_requests_Id", "group_join_requests");
+            migrationBuilder.DropIndex("IX_group_join_requests_GroupId_State_CreationTime", "group_join_requests");
+            migrationBuilder.DropIndex("IX_group_join_requests_UserId_CreationTime", "group_join_requests");
+        }
+    }
+}

GroupService.Infrastructure/Migrations/20260915000100_ManagementReceipts.cs

@@ -0,0 +1,19 @@
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+namespace GroupService.Infrastructure.Migrations;
+[DbContext(typeof(GroupDbContext))]
+[Migration("20260915000100_ManagementReceipts")]
+public class ManagementReceipts : Migration
+{
+    protected override void Up(MigrationBuilder m) => m.Sql("""
+        CREATE TABLE IF NOT EXISTS management_receipts (
+          Owner varchar(64) NOT NULL,
+          Id char(36) NOT NULL,
+          Payload longtext NOT NULL,
+          CreatedAt datetime(6) NOT NULL,
+          PRIMARY KEY (Owner, Id)
+        ) CHARACTER SET utf8mb4;
+        """);
+    // Receipts are retained on rollback: losing idempotency history can repeat a previously applied action.
+    protected override void Down(MigrationBuilder m) { }
+}

GroupService.Infrastructure/Migrations/GroupDbContextModelSnapshot.cs

@@ -227,6 +227,13 @@ namespace GroupService.Infrastructure.Migrations
 
                     b.HasKey("GroupId", "UserId");
 
+                    b.HasIndex("Id")
+                        .IsUnique();
+
+                    b.HasIndex("GroupId", "State", "CreationTime");
+
+                    b.HasIndex("UserId", "CreationTime");
+
                     b.ToTable("group_join_requests", (string)null);
                 });
 
@@ -266,6 +273,10 @@ namespace GroupService.Infrastructure.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("GroupId", "IsDeleted", "Role");
+
+                    b.HasIndex("UserId", "IsDeleted", "GroupId");
+
                     b.ToTable("group_members", (string)null);
                 });
 #pragma warning restore 612, 618