In a colander, place the cucumber slices and lightly sprinkle with salt. Let drain for 30 minutes, then pat dry with paper towels.
Meanwhile, in a large skillet, heat the oil over medium-high heat. Add the shallots and garlic, and cook, stirring, until soft and fragrant, about 2 minutes. Add the wine, bring to a boil, and cook until nearly evaporated. Remove from the heat and let cool.
In a medium bowl, whisk together the sour cream, heavy cream, vinegar, lemon zest, dill, salt, and pepper. Add the shallot mixture and whisk to combine.
In a large pot of salted water, cook the pasta until al dente. Drain and rinse with cold running water. Drain well. Toss with the sauce and cucumbers. Adjust the seasoning, to taste. Cover with plastic wrap and refrigerate until chilled, about 2 hours.
Before serving or packing for a picnic, toss with the chives and salmon. Gently fold in the salmon roe immediately before serving. Garnish with dill sprigs and serve.
