Task 583: Fix Timeline Bar Width/Behavior on Scene Switch

Status: DONE

Description

Human directive phase 33: "時間のバーの幅が誤っている。特に切り替え時。"

Multiple bugs in the inline 3D viewer's timeline controls:

1. Slider→day conversion bug: Slider input handler passed fraction (0-1) instead

of day value to updateTimelineFrame(day). Full-route worked by accident (frac≈0

at start) but local scenes were broken.

1. Scene switch stale state: switchScene() didn't update container.dataset.scene,

so the tick() loop always used the initial scene's totalDays even after switching.

1. Time display: Used Math.round(day) + "日" which shows "0日" for local scenes

(totalDays < 5 days). Added fmtDay() matching standalone HTML's formatDays().

1. Transfer label: .viewer3d-label element existed but was never populated.

Added getLabel(day) matching transfers to current time.

1. Timeline end: Play button didn't revert to ▶ when animation finished.

Added _onTimelineEnd callback and reset-on-replay logic.

Files

• ts/src/templates.ts — all 5 fixes in inline viewer script
• ts/src/templates.test.ts — 3 new sync tests