Closes#18576. Addresses three of four complaints from the readability
report; live-verified in a dashboard against a seeded task with body,
comments, and run history.
- Drawer default width 480px → 640px, exposed as the CSS var
`--hermes-kanban-drawer-width` so deployments / user themes can
override without forking the plugin.
- Bump body/meta/pre/log/run-history font sizes from the 0.65-0.75rem
cluster to the 0.78-0.85rem cluster. Long paths and code snippets in
task bodies, run metadata, and worker logs are legible again instead
of requiring a squint.
- Fix the black-text-on-dark-theme regression in fenced markdown code
blocks. Root cause: themes that don't define `--color-foreground`
(NERV, at least) leave `color: var(--color-foreground)` resolving
empty on <code>, which then falls back to the UA default (near-black)
instead of inheriting from the drawer's <body>. Fix: force
`color: inherit` on both inline and fenced code, and give the fenced
block background via `currentColor` instead of `--color-foreground`
so there's a visible card even when the theme var is absent.
Out of scope for this PR (comments added to #18576):
- Draggable resize handle (structural JS work; plugin ships built-only,
no src/ in-tree).
- Live worker-log viewer for running tasks (backend WS + component).
- Sibling fix: themes like NERV should define --color-foreground. The
current changes make the drawer robust against that gap, but the
root fix belongs in the theme layer.
