Implement BenthicBloom GNOME 50 wallpaper extension

Adds a complete GNOME Shell 50 extension with folder-based wallpaper
auto-rotation (shuffle/sequential, crossfade transitions, lock screen
sync), GStreamer-backed live/video wallpapers rendered onto the shell's
own Clutter stage, and OLED burn-in protection (pixel shifting, idle
dimming, forced periodic rotation). Includes a top-bar quick-access
indicator, a libadwaita preferences window, GSettings schema, and a
Makefile for install/packaging.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019RDqbdjsiisSU7CbQke4g8

Makefile

@@ -0,0 +1,32 @@
+UUID = benthicbloom@quinta0.github.io
+EXTENSIONS_DIR = $(HOME)/.local/share/gnome-shell/extensions
+INSTALL_DIR = $(EXTENSIONS_DIR)/$(UUID)
+SCHEMA_DIR = schemas
+
+.PHONY: all schemas build install uninstall pack clean
+
+all: build
+
+schemas:
+	glib-compile-schemas $(SCHEMA_DIR)
+
+build: schemas
+
+install: build
+	mkdir -p $(INSTALL_DIR)/lib $(INSTALL_DIR)/schemas
+	cp extension.js prefs.js metadata.json stylesheet.css $(INSTALL_DIR)/
+	cp lib/*.js $(INSTALL_DIR)/lib/
+	cp $(SCHEMA_DIR)/*.xml $(SCHEMA_DIR)/gschemas.compiled $(INSTALL_DIR)/schemas/
+	@echo "Installed to $(INSTALL_DIR)"
+	@echo "Reload GNOME Shell (Alt+F2, r, Enter on X11; log out/in on Wayland), then run:"
+	@echo "  gnome-extensions enable $(UUID)"
+
+uninstall:
+	rm -rf $(INSTALL_DIR)
+
+pack: schemas
+	gnome-extensions pack --force --extra-source=lib -o dist .
+
+clean:
+	rm -f $(SCHEMA_DIR)/gschemas.compiled
+	rm -rf dist