ipn/ipnlocal: move selfNode from peerAPIServer to peerAPIHandler

The peerAPIHandler is instantiated per PeerAPI call so it is
guaranteed to have the latest selfNode.

Signed-off-by: Maisem Ali <maisem@tailscale.com>

ipn/ipnlocal/peerapi_test.go

@@ -449,6 +449,9 @@ func TestHandlePeerAPI(t *testing.T) {
 					netip.MustParsePrefix("100.100.100.101/32"),
 				},
 			}
+			if tt.debugCap {
+				selfNode.Capabilities = append(selfNode.Capabilities, tailcfg.CapabilityDebug)
+			}
 			var e peerAPITestEnv
 			lb := &LocalBackend{
 				logf:           e.logBuf.Logf,
@@ -456,18 +459,15 @@ func TestHandlePeerAPI(t *testing.T) {
 				netMap:         &netmap.NetworkMap{SelfNode: selfNode},
 			}
 			e.ph = &peerAPIHandler{
-				isSelf: tt.isSelf,
+				isSelf:   tt.isSelf,
+				selfNode: selfNode,
 				peerNode: &tailcfg.Node{
 					ComputedName: "some-peer-name",
 				},
 				ps: &peerAPIServer{
-					b:        lb,
-					selfNode: selfNode,
+					b: lb,
 				},
 			}
-			if tt.debugCap {
-				e.ph.ps.selfNode.Capabilities = append(e.ph.ps.selfNode.Capabilities, tailcfg.CapabilityDebug)
-			}
 			var rootDir string
 			if !tt.omitRoot {
 				rootDir = t.TempDir()
@@ -507,9 +507,6 @@ func TestFileDeleteRace(t *testing.T) {
 			logf:           t.Logf,
 			capFileSharing: true,
 		},
-		selfNode: &tailcfg.Node{
-			Addresses: []netip.Prefix{netip.MustParsePrefix("100.100.100.101/32")},
-		},
 		rootDir: dir,
 	}
 	ph := &peerAPIHandler{
@@ -517,6 +514,9 @@ func TestFileDeleteRace(t *testing.T) {
 		peerNode: &tailcfg.Node{
 			ComputedName: "some-peer-name",
 		},
+		selfNode: &tailcfg.Node{
+			Addresses: []netip.Prefix{netip.MustParsePrefix("100.100.100.101/32")},
+		},
 		ps: ps,
 	}
 	buf := make([]byte, 2<<20)