feat: writing logs to the filesystem with rotation support (#1299)

* refactor: move lib/policy/config to lib/config

Signed-off-by: Xe Iaso <me@xeiaso.net>

* refactor: don't set global loggers anymore

Ref #864

You were right @kotx, it is a bad idea to set the global logger
instance.

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(config): add log sink support

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: update spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(test): go mod tidy

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: update spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(admin/policies): add logging block documentation

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: update CHANGELOG

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(cmd/anubis): revert this change, it's meant to be its own PR

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: go mod tidy

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test: add file logging smoke test

Assisted-by: GLM 4.6 via Claude Code
Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix: don't expose the old log file time format string

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/config/geoip_test.go

@@ -0,0 +1,36 @@
+package config
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestGeoIPValid(t *testing.T) {
+	for _, tt := range []struct {
+		err   error
+		input *GeoIP
+		name  string
+	}{
+		{
+			name: "basic valid",
+			input: &GeoIP{
+				Countries: []string{"CA"},
+			},
+		},
+		{
+			name: "invalid country",
+			input: &GeoIP{
+				Countries: []string{"XOB"},
+			},
+			err: ErrNotCountryCode,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.input.Valid(); !errors.Is(err, tt.err) {
+				t.Logf("want: %v", tt.err)
+				t.Logf("got:  %v", err)
+				t.Error("got wrong validation error")
+			}
+		})
+	}
+}