The corner header rendered plan.title in the 9rem name column, so it
collapsed to "..." — and the title already shows in the switcher, the
source, and the heading above the grid. Label its own column instead.
StatusLevel held green/orange/red — the RAG vocabulary CONTEXT.md
explicitly lists under _Avoid_ for the Status term, leaking a
presentation concern into the model and authored TOML. Replace with
on-track/at-risk/off-track; color now lives only in the renderer's
tone() mapping. Breaking change to authored .toml status values.
- milestones render as horizontal label flags, auto-stacked onto extra
rows with leader lines so labels in nearby weeks never collide
- "today" becomes a neutral grey column (mixed in oklab) and milestone
diamonds are grey too — red is reserved for problems (late, red status,
unmet counts), which no longer get a stray warm tint
- fix the name column to a stable width so the band aligns with the grid
- bar line begins/ends at a glyph centre — no stub past the first/last symbol
- glyph halos so the bar passes behind, not through, the symbols
- today's week is a shaded column instead of a vertical rule
- widen week columns so date labels stop colliding
- drop "slip" wording from the legend
