Terminal rendition of the desktop Star Map / Memory Graph: learned skills
and memories on a timeline, shared by `hermes journey` and the TUI
`/journey` overlay via one size-aware Python renderer
(agent/learning_graph_render.py).
- TUI overlay mirrors /agents: static chart overview + selectable slice
list → slice detail → single skill/memory body, with the shared
inverse-row selection treatment and a pinned footer.
- Reuse primitives: extract OverlayScrollbar into its own module (now
shared with agentsOverlay), scroll the item body via ScrollBox, and
unify both lists through one table-driven ListRow.
- No animation/playback in the TUI — pure data; the renderer's reveal
scrubber stays available in the CLI (`--play`, `--reveal`).
