feat(worker,data): persist interactive session id so a closed/aborted ConPTY session can be resumed

Generates the claude session id up front (--session-id <guid>) for a fresh interactive task
session and persists it to TaskEntity.InteractiveSessionId before launch, so an abort at any
point still leaves a resumable id. BuildForTaskAsync now resumes this task's own last
interactive session in preference to the latest autonomous run's session, but never across a
freshly (re)created worktree.

src/ClaudeDo.Data/Migrations/20260806111454_AddInteractiveSessionId.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ClaudeDo.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddInteractiveSessionId : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "interactive_session_id",
+                table: "tasks",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "interactive_session_id",
+                table: "tasks");
+        }
+    }
+}