Update worklog with study system fixes

worklog.md

@@ -745,3 +745,32 @@ Continue refactoring `/home/z/my-project/src/app/page.tsx` to reduce its size fu
 - Major codebase cleanup and organization
 - Critical special effects now functional
 - Comprehensive documentation for future development
+
+---
+Task ID: 1
+Agent: Main
+Task: Fix study system and game time freeze issues
+
+Work Log:
+- **Fixed git credentials**: Saved credentials to AGENTS.md file for persistence
+- **Fixed study system**: Changed from upfront mana cost to per-hour deduction
+  - Updated StudyTarget type to include `manaCostPerHour` and `totalCost`
+  - Updated study-slice.ts to calculate per-hour cost without deducting upfront
+  - Updated store.ts tick function to deduct mana each tick during study
+  - Added check for insufficient mana - pauses study and saves progress
+- **Fixed game time freeze bug**: `newTotalTicks` was referenced before being defined
+  - Moved `newTotalTicks` calculation to before study section
+  - Removed duplicate declaration in combat section
+- **Fixed mobile UI issues**:
+  - Fixed CalendarDisplay component props (was using `currentDay` but passed `day`)
+  - Added proper grid layout to calendar for mobile (7 columns) and desktop (14 columns)
+  - Fixed tabs layout from `grid-cols-8` to `flex flex-wrap` for mobile responsiveness
+  - Made tab triggers smaller on mobile with `text-xs px-2 py-1`
+- **Added `lastStudyCost` tracking** for STUDY_REFUND special effect
+
+Stage Summary:
+- Study now costs mana per hour instead of all upfront
+- Game time no longer freezes during study action
+- Mobile UI is now responsive with properly wrapping tabs
+- Calendar displays correctly on all screen sizes
+- All changes committed and pushed to Gitea