Fix backend crash (add prometheus+cryptography deps) and improve sidebar text visibility

frontend/assets/styles.css

@@ -382,6 +382,52 @@
     font-weight: 700;
 }
 
+/* ===== Dark Mode Sidebar Text Visibility ===== */
+/* Make sidebar nav items brighter and more readable */
+[data-testid="stSidebar"] [data-testid="stSidebarNav"] span {
+    color: #e0e0e0 !important;
+    font-weight: 500;
+}
+
+[data-testid="stSidebar"] [data-testid="stSidebarNav"] a {
+    color: #e0e0e0 !important;
+}
+
+[data-testid="stSidebar"] [data-testid="stSidebarNav"] a:hover span {
+    color: #ffffff !important;
+}
+
+/* Sidebar page links - make brighter */
+[data-testid="stSidebar"] [data-testid="stSidebarNavItems"] a {
+    color: #cccccc !important;
+}
+
+[data-testid="stSidebar"] [data-testid="stSidebarNavItems"] a:hover {
+    color: #ffffff !important;
+    background: rgba(255, 0, 51, 0.15) !important;
+}
+
+/* Active page in sidebar */
+[data-testid="stSidebar"] [data-testid="stSidebarNavItems"] a[aria-selected="true"] span {
+    color: #ff3355 !important;
+    font-weight: 600;
+}
+
+/* All sidebar text - ensure readable */
+[data-testid="stSidebar"] p,
+[data-testid="stSidebar"] span,
+[data-testid="stSidebar"] label,
+[data-testid="stSidebar"] div {
+    color: #d0d0d0;
+}
+
+/* Sidebar headers */
+[data-testid="stSidebar"] h1,
+[data-testid="stSidebar"] h2,
+[data-testid="stSidebar"] h3 {
+    color: #ffffff !important;
+}
+
 /* ===== Headers ===== */
 h1,
 h2,

requirements.txt

@@ -59,6 +59,10 @@ streamlit-webrtc==0.47.0
 
 # API instrumentation
 slowapi==0.1.9
+prometheus-fastapi-instrumentator==6.1.0
+
+# Encryption (required by security_encryption.py)
+cryptography==42.0.4
 
 # NOTE: TTS/melotts/coqui-tts removed for HF free tier
 # Edge TTS provides full TTS functionality as fallback