Initial commit: epaper-dashboard for 7.3" ACeP 7-Color display

- dashboard.py: plugin-based renderer with 4x4 grid layout
- admin.py: web UI with layout editor + plugin configs
- layout.py: pack algorithm, item placement, grid system
- plugins/: clock, weather, system, spotify, strava, gmail, minimax, hello
- network_watchdog.py: WiFi AP/client mode management
- waveshare_epd_init.py: vendor driver stub

test_system_thresholds.py

@@ -0,0 +1,29 @@
+"""Test: System Widget mit verschiedenen Threshold-Konfigurationen."""
+import sys; sys.path.insert(0, ".")
+from PIL import Image, ImageDraw, ImageFont
+from plugins.system import Widget as SystemW
+
+def font(s): return ImageFont.truetype("fnt/Aldrich-Regular.ttc", s)
+fonts = {str(s): font(s) for s in [16, 20, 24, 28, 32]}
+
+img = Image.new("RGB", (800, 480), (255,255,255))
+draw = ImageDraw.Draw(img)
+
+# Drei Konfigurationen nebeneinander
+configs = [
+    {"name": "Default (50/80/95, gradient)",
+     "cfg": {"bar_thresholds": "ok@50,warn@80,alert@95", "bar_gradient": True}},
+    {"name": "Strenger (30/60/85, gradient)",
+     "cfg": {"bar_thresholds": "ok@30,warn@60,alert@85", "bar_gradient": True}},
+    {"name": "Einfarbig (40/70/95)",
+     "cfg": {"bar_thresholds": "ok@40,warn@70,alert@95", "bar_gradient": False}},
+]
+for i, c in enumerate(configs):
+    x = i * 267
+    draw.text((x + 8, 5), c["name"], font=font(14), fill=(0,0,0))
+    w = SystemW({**c["cfg"], "compact": False})
+    w.fetch()
+    w.render(draw, fonts, x, 30, 260, 200)
+
+img.save("/tmp/system_thresholds.png")
+print("saved /tmp/system_thresholds.png")