Events are often scheduled before the platform (Zoom link, Slack
channel) is chosen. The current workaround is a placeholder URL like
"https://us02web.zoom.us/j/TBD", which leaks to the public page as a
broken link.
Accept the literal "TBD" (case-insensitive) in both the Mongoose
validator and the form-side validator. The public detail page renders
"Platform TBD" instead of a link when the location matches.
Deduplicate tag validation and regex escaping into shared auto-imported
utils. Add tag validation to wiki patch/batch-tag routes. Remove
duplicate tags field from event schema.
Standardizes color values and styling using the new tokens:
- Replaces hardcoded colors with semantic variables
- Updates background/text/border classes for light/dark mode
- Migrates inputs to UInput/USelect/UTextarea components
- Removes redundant style declarations
