feat: complete device management system with float budget tracking, curfew enforcement, TUI, and parallel checks

- Float-based budget tracking with precise elapsed time calculation
- Curfew enforcement (devices turn off when blocked)
- Terminal TUI with live status refresh
- Parallel device checks using ThreadPoolExecutor
- Simplified config with time range format (e.g. '15:00-20:30')
- Optimistic UI updates for budget buttons
- Bug fixes: curfew shutdown, last_check reset on offline

config.py

@@ -1,13 +1,29 @@
 """Application configuration."""
 
-# ── Budget ────────────────────────────────────────────────────────────
-BUDGET_S = 3600  # default 60 min in seconds
+# ═══════════════════════════════════════════════════════════════════════
+# CONFIGURATION — Edit these values to change behavior
+# ═══════════════════════════════════════════════════════════════════════
 
-# ── Timer ─────────────────────────────────────────────────────────────
-TICK_INTERVAL = 10  # seconds between budget check cycles
+BUDGET_S = 3600                  # default 60 min per device (in seconds)
+TICK_INTERVAL = 10               # seconds between budget check cycles
+ALLOWED_WEEKDAY = "7:00-23:30"  # Mon-Fri allowed hours
+ALLOWED_WEEKEND = "7:00-20:30"   # Sat-Sun allowed hours
 
-# ── Allowed device hours (curfew) ─────────────────────────────────────
-ALLOWED_WEEKDAY_START = 15   # Mon-Fri start hour
-ALLOWED_WEEKDAY_END = 20     # Mon-Fri end hour
-ALLOWED_WEEKEND_START = 8    # Sat-Sun start hour
-ALLOWED_END_MINUTE = 30      # End minute (all days)
+# ═══════════════════════════════════════════════════════════════════════
+
+
+def _parse_time_range(time_str: str) -> tuple[int, int]:
+    """Parse a time range string like '15:00-20:30' into (start_minutes, end_minutes).
+
+    Returns minutes since midnight for start and end times.
+    """
+    start_str, end_str = time_str.split("-")
+    sh, sm = map(int, start_str.split(":"))
+    eh, em = map(int, end_str.split(":"))
+    return sh * 60 + sm, eh * 60 + em
+
+
+# ── Parsed values (do not edit) ──────────────────────────────────────
+
+WEEKDAY_START, WEEKDAY_END = _parse_time_range(ALLOWED_WEEKDAY)
+WEEKEND_START, WEEKEND_END = _parse_time_range(ALLOWED_WEEKEND)