Add tray status model

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

enodia_sentinel/tray/__init__.py

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""Optional desktop tray applet. GUI deps live behind the [tray] extra."""

enodia_sentinel/tray/state.py

@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""Pure status model for the tray applet. No GUI or subprocess imports."""
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class TrayState:
+    running: bool
+    total_alerts: int
+    high_alerts: int
+    last_alert: str | None
+    color: str   # "green" | "amber" | "grey"
+    summary: str
+
+    @property
+    def tooltip(self) -> str:
+        return f"Enodia Sentinel — {self.summary}"
+
+
+def _high_count(counts: dict) -> int:
+    # Severity keys are stringified Severity names ("HIGH"/"CRITICAL"); be
+    # tolerant of case in case a producer lowercases them.
+    total = 0
+    for key, value in counts.items():
+        if str(key).upper() in ("HIGH", "CRITICAL"):
+            total += int(value)
+    return total
+
+
+def parse_status(status: dict | None) -> TrayState:
+    if not status:
+        return TrayState(False, 0, 0, None, "grey", "Unknown")
+    running = bool(status.get("running"))
+    total = int(status.get("total_alerts", 0))
+    high = _high_count(status.get("counts") or {})
+    last = status.get("last_alert")
+    if not running:
+        return TrayState(False, total, high, last, "grey", "Stopped")
+    if high:
+        return TrayState(
+            True, total, high, last, "amber",
+            f"Running — {high} high/critical of {total} alerts",
+        )
+    if total:
+        return TrayState(True, total, high, last, "green",
+                         f"Running — {total} alerts")
+    return TrayState(True, total, high, last, "green", "Running — no alerts")