feat: add data collection mode to projects with UI updates and migration script

backend/models.py

@@ -157,6 +157,11 @@ class Project(Base):
     project_type_id = Column(String, nullable=False)  # FK to ProjectType.id
     status = Column(String, default="active")  # active, on_hold, completed, archived, deleted
 
+    # Data collection mode: how field data reaches Terra-View.
+    # "remote"  — units have modems; data pulled via FTP/scheduler automatically
+    # "manual"  — no modem; SD cards retrieved daily and uploaded by hand
+    data_collection_mode = Column(String, default="manual")  # remote | manual
+
     # Project metadata
     client_name = Column(String, nullable=True, index=True)  # Client name (e.g., "PJ Dick")
     site_address = Column(String, nullable=True)