Add global Wine preferences tab

Phase 3 of the Wine/Proton stage (decisions 6, 9, 13, 19 in docs/testing/wine-proton.md): a global-only Wine tab modeled on the Pronunciation page, with the controller-only checkbox and a typed editable program list. Wine values flow through the preferences protocol so a global Apply reaches the live Wine settings from Phase 2 with no reader restart. Entries are validated as edited and named in-tab, blocking Apply until fixed; case-insensitive duplicates collapse. Per-application preferences expose no Wine editing and an app-scoped Apply cannot change the governing list.

internal/preferences/wine.go

@@ -0,0 +1,112 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package preferences
+
+/*
+#include <stdlib.h>
+#include "native.h"
+*/
+import "C"
+
+import (
+	"fmt"
+	"strings"
+	"unsafe"
+
+	"git.stormux.org/storm/cthulhu/internal/config"
+)
+
+func cloneWineSettings(wine config.WineSettings) config.WineSettings {
+	wine.ExcludedPrograms = append([]string(nil), wine.ExcludedPrograms...)
+	return wine
+}
+
+// validateWinePrograms reports the first entry the Wine tab cannot accept,
+// naming it so the user can fix or delete exactly that entry. Config
+// validation remains the backstop for these rules.
+func validateWinePrograms(programs []string) error {
+	if len(programs) > 256 {
+		return fmt.Errorf("Wine program \"%s\" is entry %d. At most 256 programs can be listed; delete an entry.", programs[256], 257)
+	}
+	for index, name := range programs {
+		switch {
+		case strings.TrimSpace(name) == "":
+			return fmt.Errorf("Wine program entry %d is blank. Type an executable name such as Game.exe, or delete the entry.", index+1)
+		case strings.ContainsAny(name, `/\`):
+			return fmt.Errorf("Wine program \"%s\" is a path. Type only the executable name, such as Game.exe, or delete the entry.", name)
+		case len(name) > 255:
+			return fmt.Errorf("Wine program \"%s\" is too long. Executable names may be at most 255 characters; fix or delete the entry.", name)
+		case strings.TrimSpace(name) != name || strings.ContainsAny(name, "\x00\r\n"):
+			return fmt.Errorf("Wine program \"%s\" is not a valid executable name. Remove the surrounding spaces or control characters, or delete the entry.", name)
+		}
+	}
+	return nil
+}
+
+// collapseWinePrograms keeps the first spelling of each program and drops
+// later case-insensitive duplicates. An empty list stays nil so merged
+// settings keep their existing shape.
+func collapseWinePrograms(programs []string) []string {
+	var collapsed []string
+	seen := make(map[string]bool, len(programs))
+	for _, name := range programs {
+		key := strings.ToLower(name)
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		collapsed = append(collapsed, name)
+	}
+	return collapsed
+}
+
+func normalizedWineSettings(wine config.WineSettings) (config.WineSettings, error) {
+	if err := validateWinePrograms(wine.ExcludedPrograms); err != nil {
+		return config.WineSettings{}, err
+	}
+	wine.ExcludedPrograms = collapseWinePrograms(wine.ExcludedPrograms)
+	return wine, nil
+}
+
+func setWineValidation(message string) {
+	text := C.CString(message)
+	defer C.free(unsafe.Pointer(text))
+	C.prefs_wine_validation(text)
+}
+
+func setWineValues(wine config.WineSettings) {
+	setCheck("wineControllerOnlyCheckButton", wine.ControllerOnly)
+	C.prefs_wine_clear()
+	for _, program := range wine.ExcludedPrograms {
+		name := C.CString(program)
+		C.prefs_wine_append(name)
+		C.free(unsafe.Pointer(name))
+	}
+	setWineValidation("")
+}
+
+func getWinePrograms() []string {
+	var programs []string
+	for row := 0; row < int(C.prefs_wine_count()); row++ {
+		name := C.prefs_wine_value(C.int(row))
+		programs = append(programs, C.GoString(name))
+		C.g_free(C.gpointer(name))
+	}
+	return programs
+}
+
+func (session *uiSession) refreshWineValidation() {
+	message := ""
+	if err := validateWinePrograms(getWinePrograms()); err != nil {
+		message = err.Error()
+	}
+	setWineValidation(message)
+}
+
+func getWineValues() (config.WineSettings, error) {
+	wine := config.WineSettings{ControllerOnly: getCheck("wineControllerOnlyCheckButton"),
+		ExcludedPrograms: getWinePrograms()}
+	return normalizedWineSettings(wine)
+}