v1.4 — Warm ivory theme, member avatars, code cleanup

[danialkhilji]

Summary

• Apply warm ivory theme across all pages with dark floating nav bar, custom SVG prayer icons, and night sky weather variants
• Add member avatar upload with photo display across all pages (task rows, notes, dashboard, settings)
• Merge 10 add/edit modals into 5 unified modals
• Extract shared components (GripIcon, ColourPicker, MemberDot, calendarUtils) and constants (INPUT_STYLE, TAP_SPRING, PRESET_COLOURS)
• Extract backend shared utilities (verify_member_exists, reorder_items, ReorderRequest, scheduler helper)
• Deduplicate Create/Update schemas, fix members router, reduce scheduler boilerplate
• Add screenshots to README, split into landing page + deployment/development guides, add contributing guide
• Fix 4 high-priority bugs: rotation reset, cleanup field, calendar month display, Feb 29 birthdays
• Add night sky weather with stars, hide 0% rain chance, day/night weather detection
• Add toggle for older purchased items, simplify quick-add modal, tune Isha prayer time
• 135 backend tests (up from 126), zero TypeScript errors, zero ruff lint errors

Test plan

• All 135 backend tests pass
• TypeScript compiles cleanly
• Frontend builds successfully
• Ruff lint passes with zero errors
• Visual QA on iPad and phone