US-YW8: Import Scene Timeline Data

[smith-and-web]

User Story

As a yWriter user who tracks story chronology,
I want to have my scene date/time data preserved,
So that I can reference timeline information while drafting.

Parent Epic: #123

yWriter XML Structure

<SCENE>
  <ID>1</ID>
  <Title>The Package Arrives</Title>
  
  <!-- Absolute date/time -->
  <Date>2024-03-15</Date>
  <Time>14:30</Time>
  
  <!-- Relative story day -->
  <Day>3</Day>
  <Hour>14</Hour>
  <Minute>30</Minute>
  
  <!-- Duration -->
  <LastsDays>0</LastsDays>
  <LastsHours>2</LastsHours>
  <LastsMinutes>30</LastsMinutes>
</SCENE>

Timeline Fields

Field	Description	Format
<Date>	Absolute calendar date	YYYY-MM-DD or varies
<Time>	Absolute time	HH:MM
<Day>	Story day number	Integer
<Hour>	Hour of day	0-23
<Minute>	Minute of hour	0-59
<LastsDays>	Scene duration (days)	Integer
<LastsHours>	Scene duration (hours)	Integer
<LastsMinutes>	Scene duration (minutes)	Integer

Use Cases

1. Chronological ordering: Sort scenes by timeline position
2. Timeline visualization: Show scene sequence on a timeline
3. Continuity checking: Verify scene durations don't overlap
4. Reference while drafting: "This scene happens on Day 3, afternoon"

Mapping to Kindling

Timeline data is metadata that doesn't map directly to beats or prose. Options:

1. Scene metadata: Store as scene-level attributes
2. Custom fields: If Kindling supports custom metadata fields
3. Notes: Convert to text in scene notes
4. Timeline view: If Kindling has timeline visualization (future)

Acceptance Criteria

• Imports Date field from scenes
• Imports Time field from scenes
• Imports Day field (story day number)
• Imports Hour and Minute fields
• Imports duration fields (LastsDays, LastsHours, LastsMinutes)
• Timeline data displays in scene metadata panel
• Empty/missing timeline fields handled gracefully
• Chronological sorting possible based on imported dates (if supported)

Edge Cases

• Partial data: Only Day set, no Date or Time
• Invalid dates: Malformed date strings
• Conflicting data: Both absolute (Date) and relative (Day) set
• Duration without start: Scene has duration but no start time

[smith-and-web]

Partial implementation in PR #140: Scene timeline data (date, time, day) is parsed but not stored or exposed in the UI. Kindling doesn't have a timeline feature yet. Keeping open for future enhancement.