Add link session preparation flow

- wire front link resolve/prepare routes
- add orchestrator session command handling
- update admin dashboards and device/link logic

packages/logic/domains/device/repository.ts

@@ -1,6 +1,6 @@
 import { ResultAsync, errAsync, okAsync } from "neverthrow";
 import { FlowExecCtx } from "@core/flow.execution.context";
-import { Database, asc, eq } from "@pkg/db";
+import { Database, and, asc, eq } from "@pkg/db";
 import { device } from "@pkg/db/schema";
 import { type Err } from "@pkg/result";
 import { logger } from "@pkg/logger";
@@ -135,4 +135,40 @@ export class DeviceRepository {
     ): ResultAsync<Device, Err> {
         return this.update(fctx, id, { status });
     }
+
+    allocateIfAvailable(fctx: FlowExecCtx, id: number): ResultAsync<Device, Err> {
+        return traceResultAsync({
+            name: "device.allocateIfAvailable",
+            fctx,
+            fn: () =>
+                ResultAsync.fromPromise(
+                    this.db
+                        .update(device)
+                        .set({
+                            status: DeviceStatus.BUSY,
+                            inUse: true,
+                            updatedAt: new Date(),
+                        })
+                        .where(
+                            and(
+                                eq(device.id, id),
+                                eq(device.status, DeviceStatus.ONLINE),
+                                eq(device.inUse, false),
+                            ),
+                        )
+                        .returning()
+                        .execute(),
+                    (e) =>
+                        deviceErrors.updateFailed(
+                            fctx,
+                            e instanceof Error ? e.message : String(e),
+                        ),
+                ).andThen((rows) => {
+                    if (!rows[0]) {
+                        return errAsync(deviceErrors.deviceNotAvailable(fctx, id));
+                    }
+                    return okAsync(rows[0] as Device);
+                }),
+        });
+    }
 }