Copyover (Hot-reload) for GoMud

_datafiles/world/default/templates/copyover/copyover-announce.template

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+<ansi fg="yellow-bold">
+================================================================================
+                         SERVER COPYOVER SCHEDULED
+================================================================================</ansi>
+
+<ansi fg="cyan">A server hot reload has been scheduled to apply updates.</ansi>
+
+{{if .Minutes}}<ansi fg="yellow">Time until copyover: {{.Minutes}} minute{{if ne .Minutes 1}}s{{end}}</ansi>{{end}}
+{{if .Seconds}}<ansi fg="yellow">Time until copyover: {{.Seconds}} second{{if ne .Seconds 1}}s{{end}}</ansi>{{end}}
+
+<ansi fg="white">The game will continue normally until the copyover begins.
+You will NOT be disconnected during this process.</ansi>

_datafiles/world/default/templates/copyover/copyover-build-complete.template

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+<ansi fg="green-bold">=== BUILD COMPLETE - PREPARING FOR RESTART ===</ansi>

_datafiles/world/default/templates/copyover/copyover-build-failed.template

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+<ansi fg="red-bold">=== BUILD FAILED - COPYOVER CANCELLED ===</ansi>
+
+<ansi fg="white">The build process encountered an error. The copyover has been cancelled.
+The game will continue running on the current version.</ansi>

_datafiles/world/default/templates/copyover/copyover-building.template

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+<ansi fg="cyan-bold">=== BUILDING NEW SERVER EXECUTABLE... ===</ansi>

_datafiles/world/default/templates/copyover/copyover-cancelled.template

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+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>
+<ansi fg="red-bold">            COPYOVER CANCELLED</ansi>
+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>
+
+The scheduled copyover has been <ansi fg="yellow">cancelled</ansi>.
+
+{{if .Reason}}Reason: <ansi fg="cyan">{{.Reason}}</ansi>{{end}}
+
+Normal operations will continue uninterrupted.
+
+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>

_datafiles/world/default/templates/copyover/copyover-countdown.template

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+<ansi fg="yellow-bold">=== COPYOVER IN {{.Seconds}} SECONDS ===</ansi>

_datafiles/world/default/templates/copyover/copyover-post.template

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+<ansi fg="green-bold">
+================================================================================
+                          COPYOVER COMPLETE - BUILD {{.BuildNumber}}
+================================================================================</ansi>
+
+<ansi fg="cyan">Welcome back! The server has been successfully reloaded.</ansi>
+
+<ansi fg="green">✓ All systems operational
+✓ Your session has been restored
+✓ You may continue playing</ansi>
+
+{{if .Duration}}<ansi fg="white">Copyover completed in {{.Duration}}</ansi>{{end}}

_datafiles/world/default/templates/copyover/copyover-pre.template

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+<ansi fg="yellow-bold">
+================================================================================
+                           SERVER COPYOVER IMMINENT
+================================================================================</ansi>
+
+<ansi fg="cyan">The server is about to perform a hot reload. You will remain connected
+during this process. The game will pause briefly while the new code loads.</ansi>
+
+<ansi fg="green">✓ Your character data is being saved
+✓ Your connection will be preserved  
+✓ You will be returned to your current location</ansi>
+
+<ansi fg="yellow">Please wait...</ansi>

_datafiles/world/default/templates/copyover/copyover-restarting.template

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+<ansi fg="yellow-bold">=== RESTARTING SERVER ===</ansi>

_datafiles/world/default/templates/copyover/copyover-saving.template

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+<ansi fg="cyan">=== Saving player data... ===</ansi>

_datafiles/world/empty/templates/copyover/copyover-announce.template

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+<ansi fg="yellow-bold">
+================================================================================
+                         SERVER COPYOVER SCHEDULED
+================================================================================</ansi>
+
+<ansi fg="cyan">A server hot reload has been scheduled to apply updates.</ansi>
+
+{{if .Minutes}}<ansi fg="yellow">Time until copyover: {{.Minutes}} minute{{if ne .Minutes 1}}s{{end}}</ansi>{{end}}
+{{if .Seconds}}<ansi fg="yellow">Time until copyover: {{.Seconds}} second{{if ne .Seconds 1}}s{{end}}</ansi>{{end}}
+
+<ansi fg="white">The game will continue normally until the copyover begins.
+You will NOT be disconnected during this process.</ansi>

_datafiles/world/empty/templates/copyover/copyover-build-complete.template

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+<ansi fg="green-bold">=== BUILD COMPLETE - PREPARING FOR RESTART ===</ansi>

_datafiles/world/empty/templates/copyover/copyover-build-failed.template

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+<ansi fg="red-bold">=== BUILD FAILED - COPYOVER CANCELLED ===</ansi>
+
+<ansi fg="white">The build process encountered an error. The copyover has been cancelled.
+The game will continue running on the current version.</ansi>

_datafiles/world/empty/templates/copyover/copyover-building.template

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+<ansi fg="cyan-bold">=== BUILDING NEW SERVER EXECUTABLE... ===</ansi>

_datafiles/world/empty/templates/copyover/copyover-cancelled.template

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+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>
+<ansi fg="red-bold">            COPYOVER CANCELLED</ansi>
+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>
+
+The scheduled copyover has been <ansi fg="yellow">cancelled</ansi>.
+
+{{if .Reason}}Reason: <ansi fg="cyan">{{.Reason}}</ansi>{{end}}
+
+Normal operations will continue uninterrupted.
+
+<ansi fg="red-bold">═══════════════════════════════════════════════════</ansi>

_datafiles/world/empty/templates/copyover/copyover-countdown.template

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+<ansi fg="yellow-bold">=== COPYOVER IN {{.Seconds}} SECONDS ===</ansi>

_datafiles/world/empty/templates/copyover/copyover-post.template

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+<ansi fg="green-bold">
+================================================================================
+                          COPYOVER COMPLETE - BUILD {{.BuildNumber}}
+================================================================================</ansi>
+
+<ansi fg="cyan">Welcome back! The server has been successfully reloaded.</ansi>
+
+<ansi fg="green">✓ All systems operational
+✓ Your session has been restored
+✓ You may continue playing</ansi>
+
+{{if .Duration}}<ansi fg="white">Copyover completed in {{.Duration}}</ansi>{{end}}

_datafiles/world/empty/templates/copyover/copyover-pre.template

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+<ansi fg="yellow-bold">
+================================================================================
+                           SERVER COPYOVER IMMINENT
+================================================================================</ansi>
+
+<ansi fg="cyan">The server is about to perform a hot reload. You will remain connected
+during this process. The game will pause briefly while the new code loads.</ansi>
+
+<ansi fg="green">✓ Your character data is being saved
+✓ Your connection will be preserved  
+✓ You will be returned to your current location</ansi>
+
+<ansi fg="yellow">Please wait...</ansi>

_datafiles/world/empty/templates/copyover/copyover-restarting.template

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+<ansi fg="yellow-bold">=== RESTARTING SERVER ===</ansi>

_datafiles/world/empty/templates/copyover/copyover-saving.template

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+<ansi fg="cyan">=== Saving player data... ===</ansi>

internal/combat/COPYOVER_COMBAT.md

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+# Combat System Copyover Integration
+
+This document describes how the combat system handles copyover (hot-reload) operations in GoMud.
+
+## Overview
+
+The combat system preserves all active combat states during copyover, allowing battles to continue seamlessly after the server restarts. This includes player vs mob, player vs player, and multi-target combat scenarios.
+
+## Architecture
+
+### State Preservation
+
+The combat copyover system preserves the following state:
+
+1. **Player Combat State** (`PlayerCombatState`)
+   - User ID and Room ID
+   - Active Aggro pointer (target and combat type)
+   - Damage tracking map (who dealt how much damage)
+   - Last damage timestamp
+
+2. **Mob Combat State** (`MobCombatState`)
+   - Mob ID and Instance ID
+   - Room ID for mob location
+   - Active Aggro pointer
+   - Player damage tracking
+   - Charmed relationships
+
+3. **Global State**
+   - Mob instance counter (ensures consistent IDs)
+
+### File Structure
+
+- `internal/combat/copyover.go` - Core combat state preservation
+- `internal/copyover/integrations.go` - Centralized integration with copyover system
+- `internal/copyover/manager.go` - Copyover state machine and coordination
+
+## Implementation Details
+
+### State Gathering
+
+When copyover begins, the system:
+
+1. The copyover manager calls the Combat system's Gather function
+2. Iterates through all online players and active mobs
+3. Captures combat-related state for entities in combat
+4. Returns state for central copyover system to save
+
+```go
+func GatherCombatState() (*CombatCopyoverState, error) {
+    // Collect player combat states
+    // Collect mob combat states  
+    // Save mob instance counter
+}
+```
+
+### State Restoration
+
+After copyover completes:
+
+1. The copyover manager calls the Combat system's Restore function
+2. Receives deserialized state from central system
+3. Restores mob instance counter first
+4. Re-establishes player combat states
+5. Re-establishes mob combat states
+6. Validates all aggro targets still exist
+
+```go
+func RestoreCombatState(state *CombatCopyoverState) error {
+    // Restore instance counter
+    // Restore player aggro
+    // Restore mob aggro
+    // Validate targets
+}
+```
+
+## Combat Behavior During Copyover
+
+### What Continues
+- Active combat relationships (aggro)
+- Damage tracking for attribution
+- Mob instance IDs remain consistent
+- Charmed mob relationships
+
+### What Resets
+- In-flight attack animations (resume next round)
+- Spell casting with rounds waiting (cancelled)
+- Combat messages in transit
+
+### Round Processing
+Combat rounds are atomic operations. Copyover occurs between rounds, so:
+- No partial damage calculations
+- No interrupted attack sequences
+- Combat resumes at the next full round
+
+## Integration Points
+
+### Copyover System
+The combat system is registered with the central copyover manager through:
+```go
+{
+    Name: "Combat",
+    Gather: func() (interface{}, error) {
+        return combat.GatherCombatState()
+    },
+    Restore: func(data interface{}) error {
+        if state, ok := data.(*combat.CombatCopyoverState); ok {
+            return combat.RestoreCombatState(state)
+        }
+        return fmt.Errorf("invalid combat state type")
+    },
+}
+```
+
+### Dependencies
+- `mobs.GetInstanceCounter()` / `SetInstanceCounter()`
+- Character aggro pointers
+- Room mob lists
+
+## Error Handling
+
+The system is resilient to:
+- Missing aggro targets (clears invalid aggro)
+- Changed room layouts (mobs stay in original rooms)
+- Offline players (their combat state is preserved)
+
+State save/load errors are logged but don't block copyover.
+
+## Testing
+
+See `combat_copyover_test.go` for unit tests covering:
+- State serialization/deserialization
+- Instance counter preservation
+- Combat state validation
+
+See `_datafiles/world/default/combat_copyover_test.md` for manual testing procedures.
+
+## Limitations
+
+1. **Spell Casting**: Spells with `RoundsWaiting > 0` are cancelled
+2. **Ranged Combat**: Cross-room combat requires exit validation
+3. **Temporary Effects**: Non-persistent buffs may need re-application
+
+## Future Enhancements
+
+1. Preserve spell casting state with round counters
+2. Add combat pause flags for smoother transitions  
+3. Implement combat state compression for large battles
+4. Add metrics for combat copyover performance