feat(timeline): make it a board, with the axis and the names pinned

The reader who was asked what good looks like named paimon.moe's timeline,
and the thing ours was missing is what that view never loses: on a wide
window we drew more calendar and nothing that said which day, whose game, or
which event was on screen. The date axis, the lane names and the event names
all scrolled away together — and a six-week bar starts weeks off the left
edge, so its name went with its start date and left a coloured rectangle.

So it is a pane that scrolls in both directions, with the axis stuck to the
top and every name stuck to the left. A name is sticky inside its own bar, so
it can never wander onto an event it does not belong to. The axis gained the
week the schedules are actually written in: a dated tick every Monday and a
brighter rule at each month.

The frozen label column that started this went away again — it stood on the
calendar and ate the names it was meant to keep. Lane names sit on their own
line instead, and "jump to today" sits in the board's header rather than
floating over the dates it sends you back to.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

docs/FEEDBACK.md

@@ -307,8 +307,10 @@ diagnosis in each item still holds — what changed is whether it has been acted
 | P1b Calendar → Timeline | **Done.** The tab reads "Timeline" |
 | P1c more games | **Done, four of them.** Infinity Nikki, Persona 5: The Phantom X, Reverse: 1999, Blue Archive — one commit each. Of the games named in the thread, Azur Lane and Umamusume are **declined on conduct** rather than pending, and the declined and cleared-but-unbuilt candidates are recorded in `AGENTS.md` § Scraping conduct so they are not re-litigated |
 | P1c roadmap in the colophon | **Not done** |
-| P2 colour and screenshot | **Not done** |
+| P2 colour and screenshot | **Layout done** (2026-08-18), colour untouched. The palette was left alone deliberately — the two-axis system was not what made the screenshot read as unfinished, a dense single column on a wide screen was. Past `lg` the page is now a pinned deadline rail beside the lists, the timeline is a board with its axis and names pinned, and the footer and settings are columns. The screenshot still wants reshooting |
 | P2 custom events | **Done.** PRD F13 first, then the code; `mygame:` / `myevent:` key spaces, in the export |
 
-So the outstanding work is P1b's three client changes, the colophon roadmap, the colour pass, and
-P0's build assertion — the cheapest items on the list are the ones still open.
+So the outstanding work is the colophon roadmap, P0's build assertion, and a reshoot of the promo
+screenshot. P1b is closed. The colour pass is open in name only: the palette was examined and left
+alone with the reasoning above, so what is left of P2 is the screenshot, which is now worth taking
+from a wide window.