Add Activity page with timeline view

- Timeline view showing logs grouped by day
- Filter by log type (feed/sleep/diaper)
- Toggle between timeline and calendar views
- Calendar view placeholder for future implementation

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/app/activity/page.tsx

@@ -0,0 +1,167 @@
+"use client";
+
+import { useState, useEffect } from "react";
+import Link from "next/link";
+
+type ViewMode = "timeline" | "calendar";
+type LogType = "feed" | "sleep" | "diaper";
+
+interface Log {
+  id: string;
+  type: LogType;
+  subType?: string;
+  amount?: number;
+  notes?: string;
+  loggedAt: string;
+}
+
+interface DayLogs {
+  date: string;
+  logs: Log[];
+}
+
+export default function ActivityPage() {
+  const [view, setView] = useState<ViewMode>("timeline");
+  const [logs, setLogs] = useState<Log[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [filter, setFilter] = useState<LogType | "all">("all");
+  const childId = "default";
+
+  useEffect(() => {
+    fetchLogs();
+  }, []);
+
+  const fetchLogs = async () => {
+    try {
+      const res = await fetch(`/api/logs?childId=${childId}&limit=100`);
+      const data = await res.json();
+      setLogs(data.entries || []);
+    } catch (err) {
+      console.error("Failed to fetch:", err);
+    }
+    setLoading(false);
+  };
+
+  const filteredLogs = filter === "all" ? logs : logs.filter((l) => l.type === filter);
+
+  const groupedByDay = filteredLogs.reduce((acc: DayLogs[], log) => {
+    const date = new Date(log.loggedAt).toDateString();
+    const existing = acc.find((d) => d.date === date);
+    if (existing) {
+      existing.logs.push(log);
+    } else {
+      acc.push({ date, logs: [log] });
+    }
+    return acc;
+  }, []);
+
+  const getIcon = (type: LogType) => {
+    switch (type) {
+      case "feed": return "🍼";
+      case "sleep": return "😴";
+      case "diaper": return "👶";
+      default: return "📝";
+    }
+  };
+
+  return (
+    <div className="min-h-screen bg-gradient-to-br from-rose-50 to-amber-50 dark:from-gray-900 dark:to-gray-800">
+      {/* Header */}
+      <div className="p-4 flex items-center justify-between">
+        <div className="flex items-center gap-4">
+          <Link href="/menu" className="p-2">←</Link>
+          <h1 className="text-xl font-bold">Activity</h1>
+        </div>
+        {/* View Toggle */}
+        <div className="flex bg-white dark:bg-gray-800 rounded-lg p-1">
+          <button
+            onClick={() => setView("timeline")}
+            className={`px-3 py-1 rounded-md text-sm ${view === "timeline" ? "bg-rose-400 text-white" : ""}`}
+          >
+            Timeline
+          </button>
+          <button
+            onClick={() => setView("calendar")}
+            className={`px-3 py-1 rounded-md text-sm ${view === "calendar" ? "bg-rose-400 text-white" : ""}`}
+          >
+            Calendar
+          </button>
+        </div>
+      </div>
+
+      {/* Filter */}
+      <div className="px-4 mb-4 flex gap-2 overflow-x-auto">
+        {(["all", "feed", "sleep", "diaper"] as const).map((f) => (
+          <button
+            key={f}
+            onClick={() => setFilter(f)}
+            className={`px-4 py-2 rounded-full text-sm whitespace-nowrap ${
+              filter === f
+                ? "bg-rose-400 text-white"
+                : "bg-white dark:bg-gray-800"
+            }`}
+          >
+            {f === "all" ? "All" : f.charAt(0).toUpperCase() + f.slice(1)}
+          </button>
+        ))}
+      </div>
+
+      {/* Content */}
+      <div className="px-4 pb-20">
+        {loading ? (
+          <div className="text-center py-20 text-gray-400">Loading...</div>
+        ) : view === "timeline" ? (
+          /* Timeline View */
+          groupedByDay.length === 0 ? (
+            <div className="text-center py-20 text-gray-400">
+              <div className="text-6xl mb-4">📊</div>
+              <p>No activity yet</p>
+            </div>
+          ) : (
+            <div className="space-y-6">
+              {groupedByDay.map((day) => (
+                <div key={day.date}>
+                  <div className="text-sm font-medium text-gray-500 mb-2">
+                    {new Date(day.date).toLocaleDateString("en-US", {
+                      weekday: "long",
+                      month: "short",
+                      day: "numeric",
+                    })}
+                  </div>
+                  <div className="space-y-2">
+                    {day.logs
+                      .sort((a, b) => new Date(b.loggedAt).getTime() - new Date(a.loggedAt).getTime())
+                      .map((log) => (
+                        <div key={log.id} className="flex items-center gap-3 p-3 bg-white dark:bg-gray-800 rounded-xl">
+                          <span className="text-2xl">{getIcon(log.type)}</span>
+                          <div className="flex-1">
+                            <div className="font-medium capitalize">{log.type}</div>
+                            <div className="text-sm text-gray-500">
+                              {log.subType && `${log.subType} · `}
+                              {log.amount && `${log.amount}ml`}
+                              {log.notes && ` · ${log.notes}`}
+                            </div>
+                          </div>
+                          <div className="text-sm text-gray-400">
+                            {new Date(log.loggedAt).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit" })}
+                          </div>
+                        </div>
+                      ))}
+                  </div>
+                </div>
+              ))}
+            </div>
+          )
+        ) : (
+          /* Calendar View */
+          <div className="bg-white dark:bg-gray-800 rounded-xl p-4">
+            <div className="text-center text-gray-400 py-20">
+              <div className="text-6xl mb-4">📅</div>
+              <p>Calendar view coming soon</p>
+            </div>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}