chore: modular monolith folder split (no behavior change)

app/seismo/routers/roster.py

@@ -0,0 +1,46 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+from datetime import datetime, timedelta
+from typing import Dict, Any
+import random
+
+from backend.database import get_db
+from backend.services.snapshot import emit_status_snapshot
+
+router = APIRouter(prefix="/api", tags=["roster"])
+
+
+@router.get("/status-snapshot")
+def get_status_snapshot(db: Session = Depends(get_db)):
+    """
+    Calls emit_status_snapshot() to get current fleet status.
+    This will be replaced with real Series3 emitter logic later.
+    """
+    return emit_status_snapshot()
+
+
+@router.get("/roster")
+def get_roster(db: Session = Depends(get_db)):
+    """
+    Returns list of units with their metadata and status.
+    Uses mock data for now.
+    """
+    snapshot = emit_status_snapshot()
+    units_list = []
+
+    for unit_id, unit_data in snapshot["units"].items():
+        units_list.append({
+            "id": unit_id,
+            "status": unit_data["status"],
+            "age": unit_data["age"],
+            "last_seen": unit_data["last"],
+            "deployed": unit_data["deployed"],
+            "note": unit_data.get("note", ""),
+            "last_file": unit_data.get("fname", "")
+        })
+
+    # Sort by status priority (Missing > Pending > OK) then by ID
+    status_priority = {"Missing": 0, "Pending": 1, "OK": 2}
+    units_list.sort(key=lambda x: (status_priority.get(x["status"], 3), x["id"]))
+
+    return {"units": units_list}