Add CP→CA→PI platform foundation on MapMil monorepo.

Unify parsing workers, analytics API with PostgreSQL, map UI, and PI distribution into centers/ with Docker Compose.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/storage.py

@@ -0,0 +1,39 @@
+import os
+import uuid
+from pathlib import Path
+
+UPLOAD_DIR = Path(os.getenv("UPLOAD_DIR", "/data/uploads"))
+
+ALLOWED_CONTENT_TYPES = {
+    "image/jpeg",
+    "image/png",
+    "image/gif",
+    "image/webp",
+    "video/mp4",
+    "video/webm",
+}
+
+MAX_FILE_SIZE = 20 * 1024 * 1024
+
+
+def ensure_upload_dir() -> None:
+    UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
+
+
+def is_allowed_content_type(content_type: str) -> bool:
+    return content_type in ALLOWED_CONTENT_TYPES
+
+
+def build_stored_name(original_name: str) -> str:
+    suffix = Path(original_name).suffix.lower()
+    return f"{uuid.uuid4().hex}{suffix}"
+
+
+def media_file_path(stored_name: str) -> Path:
+    return UPLOAD_DIR / stored_name
+
+
+def remove_media_file(stored_name: str) -> None:
+    path = media_file_path(stored_name)
+    if path.exists():
+        path.unlink()