- init currentModel to '' and skip assistant messages before first
session.model_change to avoid silent misattribution
- add comment documenting why inputTokens is always 0
- fix delete_file tool mapping ('Edit' -> 'Delete')
- add schema doc comment to ToolRequest optional fields
- remove catch-all from CopilotEvent union for proper TS narrowing
- add tests: pre-model-change skip, workspace.yaml quote/comment strip,
longest-prefix model display name match