fix(auth): harden multi-account profile compatibility

Preserve manual-token defaults across explicit profile refreshes and selective logout while keeping legacy marker behavior compatible.

Make profile login, refresh, switch, and logout writes rollback-safe; reject unsupported future profile versions before remote side effects; and prevent cross-profile token fallback.

Forward token overrides through usage recording, use the newly authenticated identity for post-login authorization, distinguish unavailable profile state, and propagate Windows registry deletion failures.

internal/app/usage_recording_test.go

@@ -25,6 +25,7 @@ import (
 
 type crossPlatformCoverageCaller struct {
 	args   map[string]any
+	token  string
 	dryRun bool
 }
 
@@ -33,6 +34,16 @@ func (c *crossPlatformCoverageCaller) CallTool(_ context.Context, _, _ string, a
 	return &edition.ToolResult{}, nil
 }
 
+func (c *crossPlatformCoverageCaller) CallToolWithToken(
+	_ context.Context,
+	token, _, _ string,
+	args map[string]any,
+) (*edition.ToolResult, error) {
+	c.token = token
+	c.args = args
+	return &edition.ToolResult{}, nil
+}
+
 func (*crossPlatformCoverageCaller) Format() string { return "json" }
 func (c *crossPlatformCoverageCaller) DryRun() bool { return c.dryRun }
 func (*crossPlatformCoverageCaller) Fields() string { return "id,name" }
@@ -88,6 +99,23 @@ func TestCrossPlatformCoverageRecordingToolCaller(t *testing.T) {
 		t.Fatal("sensitive text must not be recorded")
 	}
 
+	tokenCaller, ok := caller.(tokenOverrideToolCaller)
+	if !ok {
+		t.Fatal("recording caller dropped token override support")
+	}
+	if _, err := tokenCaller.CallToolWithToken(
+		context.Background(),
+		"temporary-token",
+		"contact",
+		"get_current_user_profile",
+		nil,
+	); err != nil {
+		t.Fatal(err)
+	}
+	if inner.token != "temporary-token" || len(inner.args) != 0 {
+		t.Fatalf("token override forwarding = token %q args %#v", inner.token, inner.args)
+	}
+
 	inner.dryRun = true
 	if _, err := caller.CallTool(context.Background(), "chat", "send_message", args); err != nil {
 		t.Fatal(err)
@@ -96,7 +124,7 @@ func TestCrossPlatformCoverageRecordingToolCaller(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(records) != 1 {
+	if len(records) != 2 {
 		t.Fatalf("dry-run call must not be recorded: %#v", records)
 	}
 }