Two issues with the config editor:
Layout: the page root had no height constraint and the textarea used
min-h-[500px] resize-y, causing independent scrollbars on both the
page and the editor. Fixed by adopting the Memory/Cron flex column
pattern so the editor fills the remaining viewport height with a single
scroll surface.
Highlighting: plain textarea with no visual structure for TOML.
Added a zero-dependency layered pre-overlay technique — no new npm
packages (per CLAUDE.md anti-pattern rules). A pre element sits
absolute behind a transparent textarea; highlightToml() produces HTML
colour-coding sections, keys, strings, booleans, numbers, datetimes,
and comments via per-line regex. onScroll syncs the overlay. Tab key
inserts two spaces instead of leaving focus.
dangerouslySetInnerHTML used on the pre — content is the user's own
local config, not from the network, risk equivalent to any local editor.
Risk: Low-Medium — no API or backend change. New rendering logic
in editor only.
Does not change: save/load API calls, validation, sensitive field
masking behaviour.
0aefde95f2