First commit of claude's rework in django + vanillajs fronted

apps/tools/analyzer/stats.py

@@ -0,0 +1,30 @@
+import pandas as pd
+
+
+def compute_overall_stats(df: pd.DataFrame) -> dict:
+    s = df["speed"]
+    return {
+        "min_speed": s.min(),
+        "max_speed": s.max(),
+        "mean_speed": s.mean(),
+        "std_speed": s.std(ddof=1),
+        "count": len(df),
+    }
+
+
+def compute_group_stats(groups: list) -> list:
+    result = []
+    for i, g in enumerate(groups):
+        s = g["speed"]
+        std = s.std(ddof=1) if len(g) > 1 else None
+        result.append({
+            "group_index": i + 1,
+            "count": len(g),
+            "min_speed": s.min(),
+            "max_speed": s.max(),
+            "mean_speed": s.mean(),
+            "std_speed": std,
+            "time_start": g["time"].min().strftime("%H:%M:%S"),
+            "time_end": g["time"].max().strftime("%H:%M:%S"),
+        })
+    return result