refactor: split every monolithic module into focused submodules

Each source file that had grown beyond a single concern is replaced by an identically-named directory containing focused submodules. `src/event_loop/mod.rs` (878 lines) becomes a directory with clipboard, context_menu, cursor_shape, drag, focus, handlers, invalidation, overlays_reconcile, repeat, run, surface, text_editing, and tooltip. Every widget, input handler, and theme component follows the same split. Public interfaces are unchanged — only the internal file layout moves.
image bumped from 0.25.2 to 0.25.9.

src/input/pointer/enter.rs

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: LGPL-2.1-only
+// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>
+
+use smithay_client_toolkit::seat::pointer::{ PointerEvent, PointerEventKind };
+use smithay_client_toolkit::reexports::client::
+{
+	protocol::wl_pointer::WlPointer,
+	Connection, QueueHandle,
+};
+
+use crate::app::App;
+use crate::event_loop::{ AppData, SurfaceFocus };
+
+impl<A: App> AppData<A>
+{
+	pub( super ) fn on_pointer_enter(
+		&mut self,
+		_conn:    &Connection,
+		_qh:      &QueueHandle<Self>,
+		_pointer: &WlPointer,
+		event:    &PointerEvent,
+	)
+	{
+		let focus = self.focus_for_surface( &event.surface )
+			.unwrap_or( SurfaceFocus::Main );
+		if let PointerEventKind::Enter { serial } = event.kind
+		{
+			// Pointer just entered our surface — capture the
+			// serial that wp_cursor_shape_device_v1::set_shape
+			// requires, then push the initial cursor shape
+			// *unconditionally*. Resetting `current_cursor_shape`
+			// to `None` is what forces the dispatch: the
+			// compositor was showing whatever the previous
+			// client asked for (e.g. a text I-beam from a
+			// terminal under our window), and we must claim
+			// the cursor for our surface even when the target
+			// equals what we last pushed.
+			self.last_pointer_enter_serial = serial;
+			self.current_cursor_shape = None;
+			self.dispatch_cursor_shape( focus );
+		}
+	}
+}