ipn,tailfs: tie TailFS share configuration to user profile

Previously, the configuration of which folders to share persisted across
profile changes. Now, it is tied to the user's profile.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>

cmd/tailscale/cli/cli_test.go

@@ -829,6 +829,10 @@ func TestPrefFlagMapping(t *testing.T) {
 			// Handled by TS_DEBUG_FIREWALL_MODE env var, we don't want to have
 			// a CLI flag for this. The Pref is used by c2n.
 			continue
+		case "TailFSShares":
+			// Handled by the tailscale share subcommand, we don't want a CLI
+			// flag for this.
+			continue
 		}
 		t.Errorf("unexpected new ipn.Pref field %q is not handled by up.go (see addPrefFlagMapping and checkForAccidentalSettingReverts)", prefName)
 	}

cmd/tailscale/cli/share.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"sort"
 	"strings"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
@@ -93,18 +92,10 @@ func runShareList(ctx context.Context, args []string) error {
 		return fmt.Errorf("usage: tailscale %v", shareListUsage)
 	}
 
-	sharesMap, err := localClient.TailFSShareList(ctx)
+	shares, err := localClient.TailFSShareList(ctx)
 	if err != nil {
 		return err
 	}
-	shares := make([]*tailfs.Share, 0, len(sharesMap))
-	for _, share := range sharesMap {
-		shares = append(shares, share)
-	}
-
-	sort.Slice(shares, func(i, j int) bool {
-		return shares[i].Name < shares[j].Name
-	})
 
 	longestName := 4 // "name"
 	longestPath := 4 // "path"