feat: Add dashboard support and enhance Discord webhook functionality

- Updated docker-compose.yml to expose dashboard on port 8080.
- Enhanced main.py with timezone database caching and improved state management.
- Introduced a minimal dashboard using Flask to display webhook status and notifications.
- Added templates.json for customizable embed messages in Discord notifications.
- Created templates.py for loading and saving notification templates.
- Implemented tests for dashboard rendering and main functionality.
- Added requirements for Flask and tzdata to support new features.
- Included test cases for timezone handling and template management.

templates.py

@@ -0,0 +1,98 @@
+from __future__ import annotations
+
+import json
+from copy import deepcopy
+from pathlib import Path
+
+
+DEFAULT_TEMPLATES: dict[str, dict] = {
+    "reminder_halftime": {
+        "text": "Half-time in 5 minutes!",
+        "color": 0xE67E22,
+    },
+    "halftime": {
+        "text": "Half-time!",
+        "color": 0x2ECC71,
+        "image_url": "https://copyparty.allucanget.biz/img/weed.png",
+    },
+    "reminder": {
+        "text": "This is your 5 minute reminder to 420!",
+        "color": 0xE67E22,
+    },
+    "420": {
+        "text": "Blaze it!",
+        "color": 0x2ECC71,
+        "image_url": "https://copyparty.allucanget.biz/img/weed.png",
+    },
+}
+
+
+def _normalize_templates(raw: dict) -> dict[str, dict]:
+    out: dict[str, dict] = deepcopy(DEFAULT_TEMPLATES)
+
+    if not isinstance(raw, dict):
+        return out
+
+    for key, default in DEFAULT_TEMPLATES.items():
+        incoming = raw.get(key)
+        if not isinstance(incoming, dict):
+            continue
+
+        text = incoming.get("text")
+        if isinstance(text, str):
+            out[key]["text"] = text
+
+        color = incoming.get("color")
+        if isinstance(color, int):
+            out[key]["color"] = color
+
+        image_url = incoming.get("image_url")
+        if isinstance(image_url, str) and image_url.strip():
+            out[key]["image_url"] = image_url.strip()
+        elif "image_url" in default and image_url in (None, ""):
+            # Allow clearing image_url only if explicitly set to empty.
+            out[key].pop("image_url", None)
+
+    return out
+
+
+def load_templates(path: str | Path) -> dict[str, dict]:
+    p = Path(path)
+    try:
+        if not p.exists():
+            return deepcopy(DEFAULT_TEMPLATES)
+        raw = json.loads(p.read_text(encoding="utf-8"))
+        return _normalize_templates(raw)
+    except Exception:
+        return deepcopy(DEFAULT_TEMPLATES)
+
+
+def save_templates(path: str | Path, templates: dict) -> None:
+    p = Path(path)
+    normalized = _normalize_templates(templates)
+
+    p.parent.mkdir(parents=True, exist_ok=True)
+    tmp = p.with_suffix(p.suffix + ".tmp")
+    tmp.write_text(json.dumps(normalized, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+    tmp.replace(p)
+
+
+def parse_color(value: str) -> int:
+    """Parse color from '#RRGGBB', 'RRGGBB', '0xRRGGBB', or decimal."""
+    s = (value or "").strip().lower()
+    if not s:
+        raise ValueError("color is required")
+
+    if s.startswith("#"):
+        s = s[1:]
+
+    base = 16
+    if s.startswith("0x"):
+        s = s[2:]
+    elif all(c.isdigit() for c in s):
+        base = 10
+
+    color = int(s, base)
+    if color < 0 or color > 0xFFFFFF:
+        raise ValueError("color must be between 0 and 0xFFFFFF")
+    return color