fix(dashboard): let the hourly chart's hour labels rotate instead of overlapping

[DiegoDAF]

The problem

On the Average Hourly Distribution chart, the hour labels collapse into an unreadable smear once the window is narrower than roughly 1000px:

00:0001:0002:0003:00… — 24 ticks fighting for space that fits maybe half of them.

The cause is in the x-axis config (dashboard.py, renderHourlyChart):

x: { ticks: { color: C.axis, maxRotation: 0, autoSkip: false, font: { size: 10 } }, ... }

maxRotation: 0 forbids tilting and autoSkip: false forbids dropping ticks, so Chart.js has no escape hatch left — it draws all 24 HH:00 labels at whatever width is available and lets them overlap. On a wide monitor there's enough room that nothing looks wrong, which is presumably why it went unnoticed.

The fix

One line — allow rotation, keep every hour labelled:

x: { ticks: { color: C.axis, minRotation: 0, maxRotation: 90, autoSkip: false, font: { size: 10 } }, ... }

Chart.js now picks the smallest angle that avoids collisions, so nothing changes on wide screens and the labels tilt progressively as the chart narrows. autoSkip: false is kept deliberately: for an hour-of-day axis, hiding every other hour is worse than tilting.

This also brings the chart in line with the Daily Token Usage chart directly above it, which already rotates its date labels — so the two axes no longer disagree about how to handle crowding.

Verification

Headless Chrome against a live dashboard, at two widths:

Viewport	Result
900px (where the overlap was reported)	labels tilt to ~45°, all 24 readable
560px (narrow panel / mobile)	labels tilt further, ~65°, still no overlap
wide	unchanged — horizontal, as before

python -m unittest discover -s tests → 147 tests, OK.

Note on the CHANGELOG

The bullet lands under ## v1.5.6 — TBD, which #161 also opens. If #161 merges first this will conflict on that heading — trivial to resolve, and happy to rebase on request.