Add Seismo Fleet Manager backend v0.1

Implemented FastAPI backend with SQLite database for tracking seismograph fleet status:
- database.py: SQLAlchemy setup with SQLite
- models.py: Emitter model with id, unit_type, last_seen, last_file, status, notes
- routes.py: POST /emitters/report and GET /fleet/status endpoints
- main.py: FastAPI app initialization with CORS support
- requirements.txt: Dependencies (FastAPI, SQLAlchemy, uvicorn)

routes.py

@@ -0,0 +1,82 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional, List
+
+from database import get_db
+from models import Emitter
+
+router = APIRouter()
+
+
+# Pydantic schemas for request/response validation
+class EmitterReport(BaseModel):
+    unit: str
+    unit_type: str
+    timestamp: str
+    file: str
+    status: str
+
+
+class EmitterResponse(BaseModel):
+    id: str
+    unit_type: str
+    last_seen: datetime
+    last_file: str
+    status: str
+    notes: Optional[str] = None
+
+    class Config:
+        from_attributes = True
+
+
+@router.post("/emitters/report", status_code=200)
+def report_emitter(report: EmitterReport, db: Session = Depends(get_db)):
+    """
+    Endpoint for emitters to report their status.
+    Creates a new emitter if it doesn't exist, or updates an existing one.
+    """
+    try:
+        # Parse the timestamp
+        timestamp = datetime.fromisoformat(report.timestamp.replace('Z', '+00:00'))
+    except ValueError:
+        raise HTTPException(status_code=400, detail="Invalid timestamp format")
+
+    # Check if emitter already exists
+    emitter = db.query(Emitter).filter(Emitter.id == report.unit).first()
+
+    if emitter:
+        # Update existing emitter
+        emitter.unit_type = report.unit_type
+        emitter.last_seen = timestamp
+        emitter.last_file = report.file
+        emitter.status = report.status
+    else:
+        # Create new emitter
+        emitter = Emitter(
+            id=report.unit,
+            unit_type=report.unit_type,
+            last_seen=timestamp,
+            last_file=report.file,
+            status=report.status
+        )
+        db.add(emitter)
+
+    db.commit()
+    db.refresh(emitter)
+
+    return {
+        "message": "Emitter report received",
+        "unit": emitter.id,
+        "status": emitter.status
+    }
+
+
+@router.get("/fleet/status", response_model=List[EmitterResponse])
+def get_fleet_status(db: Session = Depends(get_db)):
+    """
+    Returns a list of all emitters and their current status.
+    """
+    emitters = db.query(Emitter).all()
+    return emitters