Comprehensive dark-mode styling pass covering:

- Submenu link-buttons styled as pills with hover/active/focus states - Custom dark-themed checkboxes replacing browser defaults - Submit/action buttons with hover, active, and disabled states - Wiki editor: tab bar, toolbar layout, fieldsets - Chat: centered layout, blue-tinted bubbles, styled input/buttons, mobile - Timeline: fileage/tree-view hover overrides (was bright white) - Diff: subtle green/red ins/del, diffskip rows, SBS marker columns - Annotate: dark overlay on inline pastel backgrounds - Forum: search form layout, post containers, debug panel - Tickets: tktDspValue dark surface instead of light grey - Security audit: capsumRead/Write/Off with dark-appropriate colors - Search form: proper flex layout with text input priority - Sitemap dropdown: multi-column with mobile single-column fallback - Header: logo image from /logo instead of F text mark - span.error/mark: dark-mode yellow highlight treatment - Various Fossil built-in light-theme color overrides check-in: 5e434ca14e user: dmestas tags: trunk