Add controller presets management (#581)

## Link to GitHub Issue or related Pull Request, if one exists
Implements #579.

## Description of change

### Controller Presets

Add a new "Presets" tab to spicecfg that allows users to save, load, and
manage controller binding presets.

#### Save Presets
- Capture all current button, analog, and light bindings as a preset
- "Assign Labels" dialog prompts the user to name each source device
(e.g. "Player 1", "Player 2") before saving
- Device IDs are replaced with these labels, making presets portable
across different machines
- Presets are stored in `%APPDATA%/spice2x/spicetools_presets.xml`

#### Load / Apply Presets
- Preset list shows name, type (Built-in / User), and binding counts
- Apply dialog maps each preset source label to a connected device or
keyboard
- Bindings are applied per-source, supporting multi-device setups (e.g.
two PHOENIXWAN controllers)

#### Edit / Delete Presets
- Rename source labels in saved presets (propagates to all bindings)
- Delete user presets

#### Built-in Presets
- PHOENIXWAN preset for Beatmania IIDX: P1/P2 buttons (1-7, Start,
EFFECT, VEFX), turntable analogs, and button lights

## Testing

* [x] Open spicecfg, go to Buttons tab, verify Presets section loads
* [x] Verify PHOENIXWAN builtin preset appears for Beatmania IIDX
* [x] Save a new preset: confirm "Assign Labels" dialog appears with
device descriptions as defaults
* [x] Apply a preset: confirm source column shows labels, popup does not
shrink
* [x] Edit labels on a saved preset: confirm rename propagates to all
bindings
* [x] Hover over a device source tooltip: confirm vKey shows as number

src/spice2x/overlay/windows/config.h

@@ -8,6 +8,7 @@
 #include "rawinput/device.h"
 #include "external/imgui/imgui_filebrowser.h"
 #include "patch_manager.h"
+#include "controller_presets.h"
 
 namespace overlay::windows {
 
@@ -23,6 +24,7 @@ namespace overlay::windows {
         CONFIG_TAB_OPTIONS,
         CONFIG_TAB_ADVANCED,
         CONFIG_TAB_DEV,
+        CONFIG_TAB_PRESETS,
         CONFIG_TAB_SEARCH,
     };
 
@@ -93,6 +95,22 @@ namespace overlay::windows {
         ImGui::FileBrowser keypads_card_select_browser[2];
         char keypads_card_number[2][18] {};
 
+        // presets tab
+        std::vector<ControllerTemplate> templates_cache;
+        bool templates_cache_dirty = true;
+        int templates_selected = -1;
+        char template_save_name[256] = {};
+        // per-source target mapping: source index -> selected target device index
+        std::vector<int> template_target_selection;
+        // deferred popup flags (to avoid ImGui ID stack mismatch inside tables)
+        bool template_apply_open = false;
+        bool template_edit_open = false;
+        bool template_save_labels_open = false;
+        bool template_delete_open = false;
+        ControllerTemplate template_pending_save;
+        std::vector<std::string> template_save_sources;
+        std::vector<std::string> template_save_labels;
+
         // patches tab
         std::unique_ptr<PatchManager> patch_manager;
 
@@ -146,6 +164,13 @@ namespace overlay::windows {
             std::vector<MatchEntry> &matched,
             std::vector<MatchEntry> &unmatched);
 
+        void build_presets();
+        void clear_all_bindings();
+        void apply_template_source(const ControllerTemplate &tmpl,
+                                   const std::string &source_filter,
+                                   const std::string &target_device);
+        ControllerTemplate capture_current_bindings(const std::string &name);
+
         void build_cards();
         std::string build_option_value_picker_title(const OptionDefinition& option);
         void build_option_value_picker(Option& option);