Sync to Pi: alle Features die live deployed sind

Aus dem Backup und Live-Pull vom Pi (10.11.3.144):
- dashboard.py: Grid-Linien nur im freien Hintergrund (nicht durch Widgets)
- templates/index.html: komplett redesigned mit Sidebar + Topbar + Toast + Modal
- plugins/clock.py: responsive Layout (1x1 bis 4x4)
- plugins/system.py, weather.py, minimax.py: mit Threshold-Bars und Color-Variants
- plugins/base.py: NEU — fetch_with_retry Helper (3x retry mit backoff)
  + render_error_banner für fehlgeschlagene API-Plugins
  (grosses rotes "!" Icon mit Plugin-Name und Fehler statt Crash)

Cleanup: Helfer-Chaos (renderer.py/2/3, design_a/b/c.html, clock_classic.py,
23x clock_*.png, alte test_*.py) wurde bereits im vorherigen Commit entfernt.

Co-Authored-By: Hermes <noreply@hermes.local>

network_watchdog.py

@@ -229,9 +229,50 @@ def is_wifi_connected() -> bool:
     return "connected" in out.lower()
 
 
+# ============================================================================
+# Recovery threshold helper (used by admin.py)
+# ============================================================================
+def get_recovery_threshold() -> int:
+    """Liest recovery_threshold_s aus config.json (default 60s)."""
+    try:
+        from pathlib import Path as _P
+        cfg_path = _P("/home/koptikp/epaper-dashboard/port/config.json")
+        if cfg_path.exists():
+            import json as _json
+            cfg = _json.loads(cfg_path.read_text())
+            return int(cfg.get("recovery_threshold_s", 60))
+    except Exception:
+        pass
+    return 60
+
+
 # ============================================================================
 # Watchdog
 # ============================================================================
+def _check_recovery_needed(state: dict, threshold_s: int) -> dict:
+    """Entscheidet, ob die Recovery-Info UI angezeigt werden soll.
+
+    Returns dict mit:
+      show: bool
+      reason: 'offline' | 'ap_active' | 'connecting_timeout' | 'no_ip'
+      duration_s: Sekunden im aktuellen (nicht-client) Zustand
+    """
+    mode = state.get("mode", "unknown")
+    if mode == "client":
+        return {"show": False, "reason": "client", "duration_s": 0}
+    # Im AP-Modus: immer anzeigen
+    if mode == "ap":
+        return {"show": True, "reason": "ap_active", "duration_s": state.get("since_change_s", 0)}
+    if mode == "offline":
+        return {"show": True, "reason": "offline", "duration_s": state.get("since_change_s", 0)}
+    if mode == "connecting":
+        # Connecting dauert zu lange? Zeige info.
+        return {"show": state.get("since_change_s", 0) > threshold_s,
+                "reason": "connecting_timeout",
+                "duration_s": state.get("since_change_s", 0)}
+    return {"show": False, "reason": "unknown", "duration_s": state.get("since_change_s", 0)}
+
+
 class Watchdog:
     def __init__(self):
         self.state = NetState()