タスクを時間軸に並べるガントタブを追加

薄いバーで開始〜終了の全体、濃い部分で応答が動いていた区間を重ねて描く。
放置していた時間や、セッションを並行して動かしていた時間が見える。

- /api/timeline: セッションごとに全体の範囲と応答中の区間 (spans) を返す
  (隙間 1 秒以内のターンは結合、期間指定 days= / 全期間、CSV も可)
- ガントタブ: 1日/3日/7日/14日/30日/全期間の切替、1〜3日では時刻目盛りに
  自動で切替、土日の帯・日境界線・現在時刻の点線、横断時はプロジェクト別の色
- 行のホバーで内訳、クリックでそのタスクのやりとりを開く
- ラベル列とバーの行を22pxで揃え、時間軸ヘッダは縦スクロール中も固定
- ペイン幅に応じてラベル幅を詰め、横スクロールを出さない

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

chktime.py

@@ -496,6 +496,91 @@ class Store:
             },
         }
 
+    def timeline(self, project_id=None, days=7):
+        """ガント表示用。セッションを1本のバーとして、内側に応答中の区間を返す。
+
+        spans は各ターンの [発言時刻, 応答完了] を、隙間 1 秒以内なら繋げたもの。
+        """
+        paths = {p["id"]: p["path"] for p in self.projects()}
+        if project_id:
+            if project_id not in paths:
+                raise FileNotFoundError(project_id)
+            targets = [project_id]
+        else:
+            targets = list(paths)
+
+        now = datetime.now().timestamp()
+        t0 = None
+        if days and days > 0:
+            midnight = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
+            t0 = (midnight - timedelta(days=days - 1)).timestamp()
+
+        rows = []
+        per_project = {}
+        for pid in targets:
+            for path in self.session_files(pid):
+                session = self.session(path)
+                start, end = session["startEpoch"], session["endEpoch"]
+                if start is None:
+                    continue
+                if t0 is not None and (end if end is not None else start) < t0:
+                    continue
+                spans = []
+                active = 0
+                for turn in session["turns"]:
+                    a = turn["ts"]
+                    if a is None:
+                        continue
+                    b = turn["endTs"] if turn["endTs"] is not None else a
+                    if t0 is not None and b < t0:
+                        continue
+                    active += turn["durMs"] or 0
+                    if spans and a - spans[-1][1] <= 1:
+                        spans[-1][1] = max(spans[-1][1], b)
+                    else:
+                        spans.append([a, b])
+                rows.append(
+                    {
+                        "id": session["id"],
+                        "project": pid,
+                        "projectPath": session.get("cwd") or paths.get(pid, pid),
+                        "title": session["title"],
+                        "start": session["start"],
+                        "end": session["end"],
+                        "startEpoch": round(start, 1),
+                        "endEpoch": round(end if end is not None else start, 1),
+                        "wallMs": session["wallMs"],
+                        "activeMs": active,
+                        "turnCount": session["turnCount"],
+                        "toolCalls": session["toolCalls"],
+                        "spans": [[round(a, 1), round(b, 1)] for a, b in spans],
+                    }
+                )
+                total = per_project.setdefault(pid, {"activeMs": 0, "sessions": 0})
+                total["activeMs"] += active
+                total["sessions"] += 1
+
+        rows.sort(key=lambda s: s["startEpoch"])
+        if t0 is None:
+            t0 = min((s["startEpoch"] for s in rows), default=now)
+        t1 = max([now] + [s["endEpoch"] for s in rows])
+        projects = sorted(
+            (
+                {"id": pid, "path": paths.get(pid, pid), "activeMs": v["activeMs"], "sessions": v["sessions"]}
+                for pid, v in per_project.items()
+            ),
+            key=lambda p: -p["activeMs"],
+        )
+        return {
+            "scope": project_id or "",
+            "rangeDays": days if days and days > 0 else 0,
+            "from": round(t0, 1),
+            "to": round(t1, 1),
+            "now": round(now, 1),
+            "sessions": rows,
+            "projects": projects,
+        }
+
     def clear(self):
         with self._lock:
             self._cache.clear()
@@ -589,6 +674,18 @@ def turns_csv(session):
     return buf.getvalue()
 
 
+def timeline_csv(data):
+    buf = io.StringIO(newline="")
+    writer = csv.writer(buf)
+    writer.writerow(["project", "session_id", "title", "start", "end", "wall", "active", "turns", "tool_calls"])
+    for s in data["sessions"]:
+        writer.writerow(
+            [s["projectPath"], s["id"], s["title"], s["start"] or "", s["end"] or "",
+             fmt_dur(s["wallMs"]), fmt_dur(s["activeMs"]), s["turnCount"], s["toolCalls"]]
+        )
+    return buf.getvalue()
+
+
 class Server(ThreadingHTTPServer):
     # Windows では SO_REUSEADDR が「使用中のポートにも bind できる」意味になり、
     # 二重起動が検出できなくなるため無効にする。
@@ -637,6 +734,12 @@ class Handler(BaseHTTPRequestHandler):
             if query.get("format", [""])[0] == "csv":
                 return self.send_text(daily_csv(data), "text/csv", f"{project or 'all'}-daily.csv")
             return self.send_json(data)
+        if route == "/api/timeline":
+            project = query.get("project", [""])[0]
+            data = store.timeline(project or None, parse_days(query.get("days", ["7"])[0]))
+            if query.get("format", [""])[0] == "csv":
+                return self.send_text(timeline_csv(data), "text/csv", f"{project or 'all'}-timeline.csv")
+            return self.send_json(data)
         if route == "/api/session":
             project = query.get("project", [""])[0]
             session_id = query.get("id", [""])[0]