add plugin settings, per-tile refresh, settings menu, touch-friendly UI

- Plugin settings infrastructure in PluginManager with config/plugin_settings.cfg
  storage, manifest [settings] sections, CRUD API, plugin_setting_changed signal
- Per-tile refresh intervals: 100ms base tick, per-tile update_interval_ms
  metadata, dynamic tween durations clamped to refresh window
- Settings menu (PopupPanel) with General/Plugins/About tabs, plugin
  activation toggles, per-plugin settings cog buttons
- Plugin settings popup (PopupPanel) with dynamic UI from setting definitions
  (SpinBox/CheckBox/LineEdit), auto-save on change
- Modal behavior: exclusive = true on settings windows
- Touch-friendly sizing: enlarged close buttons, cog buttons, controls, spacing
- Red corner close button redesign with rounded corners, hover/pressed states
- Split system_monitor into local_system_monitor (CPU, Memory) and test plugins
- Plugin activation/deactivation with layout preservation

autoload/plugin_manager.gd

@@ -5,19 +5,30 @@ extends Node
 
 signal plugin_loaded(plugin_id: String, plugin_name: String)
 signal plugin_load_failed(plugin_id: String, reason: String)
+signal plugin_active_changed(plugin_id: String, active: bool)
+signal plugin_setting_changed(plugin_id: String, key: String, value: Variant)
 
 ## All loaded plugin data: plugin_id -> Dictionary
 var _plugins: Dictionary = {}
 
+## Tracks which plugins are active (plugin_id -> bool). Default true.
+var _plugin_active: Dictionary = {}
+
 ## All tile definitions: tile_id -> Dictionary
 var _tiles: Dictionary = {}
 
 ## Plugin-id -> Array[tile_id] for reverse lookup
 var _plugin_tiles: Dictionary = {}
 
+## Per-plugin settings: plugin_id -> { key -> value }
+var _plugin_settings: Dictionary = {}
+
+const PLUGIN_SETTINGS_PATH: String = "res://config/plugin_settings.cfg"
+
 
 func _ready() -> void:
 	_scan_plugins()
+	_load_plugin_settings()
 
 
 ## Scan res://plugins/*/plugin.cfg and load all manifests.
@@ -57,6 +68,7 @@ func _load_manifest(plugin_id: String, path: String) -> void:
 		base_path = path.get_base_dir(),
 	}
 	_plugins[plugin_id] = plugin_info
+	_plugin_active[plugin_id] = true
 
 	# Load tile definitions
 	var tile_count: int = cfg.get_value("tiles", "count", 0)
@@ -91,6 +103,31 @@ func _load_manifest(plugin_id: String, path: String) -> void:
 			_plugin_tiles[plugin_id] = []
 		_plugin_tiles[plugin_id].append(scoped_id)
 
+	# Load setting definitions
+	var setting_defs: Array[Dictionary] = []
+	var setting_count: int = cfg.get_value("settings", "count", 0)
+	for i in range(setting_count):
+		var s_section := "setting_%d" % i
+		var skey: String = cfg.get_value(s_section, "key", "")
+		if skey.is_empty():
+			continue
+		var sd: Dictionary = {
+			key = skey,
+			label = cfg.get_value(s_section, "label", skey),
+			type = cfg.get_value(s_section, "type", "string"),
+		}
+		# Read optional fields that don't have a default value
+		if cfg.has_section_key(s_section, "default"):
+			sd.default = cfg.get_value(s_section, "default")
+		if cfg.has_section_key(s_section, "min"):
+			sd.min = cfg.get_value(s_section, "min")
+		if cfg.has_section_key(s_section, "max"):
+			sd.max = cfg.get_value(s_section, "max")
+		if cfg.has_section_key(s_section, "step"):
+			sd.step = cfg.get_value(s_section, "step")
+		setting_defs.append(sd)
+	plugin_info.settings = setting_defs
+
 	plugin_loaded.emit(plugin_id, plugin_info.name)
 
 
@@ -107,6 +144,71 @@ func get_plugin(plugin_id: String) -> Dictionary:
 	return _plugins.get(plugin_id, {})
 
 
+## Returns true if the plugin is active (tiles can be instantiated).
+func is_plugin_active(plugin_id: String) -> bool:
+	return _plugin_active.get(plugin_id, true)
+
+
+## Enable or disable a plugin. When disabled, tiles cannot be instantiated.
+func set_plugin_active(plugin_id: String, active: bool) -> void:
+	if _plugin_active.get(plugin_id, true) == active:
+		return
+	_plugin_active[plugin_id] = active
+	plugin_active_changed.emit(plugin_id, active)
+
+
+## Returns setting definitions for a plugin (from its manifest).
+func get_plugin_settings(plugin_id: String) -> Array[Dictionary]:
+	var info: Dictionary = _plugins.get(plugin_id, {})
+	var defs: Array = info.get("settings", [])
+	return defs.duplicate()
+
+
+## Read a plugin setting value, falling back to the default from the manifest.
+func get_plugin_setting(plugin_id: String, key: String, default_value: Variant = null) -> Variant:
+	if _plugin_settings.has(plugin_id) and _plugin_settings[plugin_id].has(key):
+		return _plugin_settings[plugin_id][key]
+	# Fall back to manifest default
+	var info: Dictionary = _plugins.get(plugin_id, {})
+	for sd in info.get("settings", []):
+		if sd.get("key", "") == key:
+			return sd.get("default", default_value)
+	return default_value
+
+
+## Persist a plugin setting and emit change signal.
+func set_plugin_setting(plugin_id: String, key: String, value: Variant) -> void:
+	if not _plugin_settings.has(plugin_id):
+		_plugin_settings[plugin_id] = {}
+	if _plugin_settings[plugin_id].get(key) == value:
+		return
+	_plugin_settings[plugin_id][key] = value
+	_save_plugin_settings()
+	plugin_setting_changed.emit(plugin_id, key, value)
+
+
+func _load_plugin_settings() -> void:
+	var cfg := ConfigFile.new()
+	if cfg.load(PLUGIN_SETTINGS_PATH) != OK:
+		return
+	for section in cfg.get_sections():
+		_plugin_settings[section] = {}
+		for key in cfg.get_section_keys(section):
+			_plugin_settings[section][key] = cfg.get_value(section, key)
+
+
+func _save_plugin_settings() -> void:
+	var cfg := ConfigFile.new()
+	for pid in _plugin_settings:
+		for key in _plugin_settings[pid]:
+			cfg.set_value(pid, key, _plugin_settings[pid][key])
+	# Only write if there's data
+	if cfg.get_sections().is_empty():
+		return
+	DirAccess.make_dir_recursive_absolute("res://config")
+	cfg.save(PLUGIN_SETTINGS_PATH)
+
+
 ## Returns all tile definitions across all plugins.
 func get_all_tile_defs() -> Array[Dictionary]:
 	var result: Array[Dictionary] = []
@@ -134,6 +236,10 @@ func instantiate_tile(tile_id: String) -> Control:
 	var def: Dictionary = _tiles.get(tile_id, {})
 	if def.is_empty():
 		return null
+	# Don't instantiate tiles from inactive plugins
+	var pid: String = def.get("plugin_id", "")
+	if not pid.is_empty() and not is_plugin_active(pid):
+		return null
 	var scene_path: String = def.get("scene", "")
 	if scene_path.is_empty():
 		return null