Consolidate scripts, add requirements.txt, remove dead files

Remove entropy-rng-cam.py and entropy-rng-opencv.py, which were
superseded by entropy.py (args, loop mode, DRBG) and carried the same
unused-entropy bug. Remove the empty 0-byte `file`. Add requirements.txt
with pinned opencv and the FastAPI stack for the upcoming API stage.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

entropy-rng-cam.py

@@ -1,47 +0,0 @@
-import hashlib
-import requests
-from io import BytesIO
-from PIL import Image
-import secrets
-
-def fetch_single_frame(url):
-    response = requests.get(url, stream=True)
-    boundary = b'--myboundary'
-    data = b''
-    in_frame = False
-    frame_data = b''
-    for chunk in response.iter_content(chunk_size=1024):
-        data += chunk
-        if not in_frame and boundary in data:
-            in_frame = True
-            data = data.split(boundary, 1)[1]
-        if in_frame and b'Content-Type: image/jpeg' in data:
-            parts = data.split(b'\r\n\r\n', 1)
-            if len(parts) > 1:
-                frame_part = parts[1]
-                if b'\r\n--myboundary' in frame_part:
-                    frame_data = frame_part.split(b'\r\n--myboundary', 1)[0]
-                    try:
-                        return Image.open(BytesIO(frame_data))
-                    except Exception as e:
-                        print(f"Error processing frame: {e}")
-                        return None
-    raise ValueError("No valid frame found in the stream.")
-
-def generate_random_numbers(frame, bit_lengths=[16, 32, 64, 128, 256]):
-    img_bytes = frame.resize((100, 100)).tobytes()
-    entropy = hashlib.sha256(img_bytes).digest()
-    # Use secrets.randbits directly
-    return {length: secrets.randbits(length) for length in bit_lengths}
-
-url = "http://192.168.0.200/mjpg/video.mjpg"
-try:
-    frame = fetch_single_frame(url)
-    if frame:
-        random_numbers = generate_random_numbers(frame)
-        for length, number in random_numbers.items():
-            print(f"{length}-bit random number: {hex(number)}")
-    else:
-        print("Failed to extract a valid frame.")
-except Exception as e:
-    print(f"Error: {e}")

entropy-rng-opencv.py

@@ -1,27 +0,0 @@
-import cv2
-import hashlib
-import secrets
-
-def fetch_frame_opencv(url):
-    cap = cv2.VideoCapture(url)
-    ret, frame = cap.read()
-    cap.release()
-    if not ret:
-        raise ValueError("Failed to fetch frame.")
-    return frame
-
-def generate_random_numbers(frame, bit_lengths=[16, 32, 64, 128, 256]):
-    _, img_encoded = cv2.imencode('.jpg', frame)
-    img_bytes = img_encoded.tobytes()
-    entropy = hashlib.sha256(img_bytes).digest()
-    # Use secrets.randbits directly
-    return {length: secrets.randbits(length) for length in bit_lengths}
-
-url = "http://192.168.0.200/mjpg/video.mjpg"
-try:
-    frame = fetch_frame_opencv(url)
-    random_numbers = generate_random_numbers(frame)
-    for length, number in random_numbers.items():
-        print(f"{length}-bit random number: {hex(number)}")
-except Exception as e:
-    print(f"Error: {e}")

requirements.txt

@@ -0,0 +1,5 @@
+# Camera entropy source dependencies
+opencv-python>=4.8,<5
+# FastAPI stack for the entropy service (added in the API stage)
+fastapi>=0.110
+uvicorn[standard]>=0.29