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_grid_v2.py

@@ -0,0 +1,32 @@
+import sys; sys.path.insert(0, ".")
+import json
+from layout import Item
+from dashboard import render_full, load_fonts
+
+cfg = json.load(open("config.json"))
+items = [Item.from_dict(d) for d in cfg["layout"]["items"]]
+plugins = cfg.get("plugin_configs", {})
+
+from plugins.base import all_widget_classes
+classes = {c.name: c for c in all_widget_classes()}
+widgets = []
+for it in items:
+    cls = classes.get(it.plugin)
+    if cls:
+        try:
+            w = cls(plugins.get(it.plugin, {}))
+            w.fetch()
+            widgets.append(w)
+        except Exception as e:
+            print(f"widget {it.plugin} failed: {e}")
+            widgets.append(None)
+    else:
+        widgets.append(None)
+
+fonts = load_fonts()
+print("items:", [(i.id, i.plugin, i.x, i.y, i.w, i.h) for i in items])
+print("widgets:", [w.name if w else None for w in widgets])
+
+img = render_full(items, widgets, fonts)
+img.save("/tmp/render_grid_v2.png")
+print(f"saved /tmp/render_grid_v2.png  size={img.size}")