docs: sync builtin wiki with server registrations
- Update builtin-context (now, datetime, gv; remove baram_time)
- Update builtin-character (has_items, equipment_off, exchange, mimic, colors, spell, world, ad, web, reward, mail, marriage; remove can_start_quest)
- Expand builtin-life stat APIs and update()
- Add script and appearance to builtin-object; block to builtin-map
- Fix builtin-quest and achievement; align builtin-model with fb.model.* registrations
docs: update quest builtin functions documentation
- Add getter/setter functionality for step(), progress(), and param() functions
- Update anchor links to use namespace-style format
- Improve examples with practical usage patterns
- Update parameter types from integer to number for consistency
- Add comprehensive documentation for new setter capabilities
fix: correct anchor links in builtin-quest.md
- Fix table of contents links to use simple #function format
- Remove complex namespace-style HTML anchor tags
- Align with other wiki document formatting standards
docs: add quest builtin functions documentation
- Add comprehensive quest object functions documentation with @wiki.mdc formatting
- Add quest model functions to builtin-model.md
- Add character quest functions to builtin-character.md
- Update main builtin.md index with quest link
- Include all modified files with proper namespace anchors