Add persistent and repeatable NPC tasks

[RANGROO]

Summary

• add persistent NPC tasks for meetings, message delivery, fetch work, escorts, errands, and other future duties
• expose CreateTasks, ResolveTask, and CancelTask as server actions
• support one-time and repeating schedules based on in-game hours
• structure accepted duties through the NPC profile's Formatter LLM in a separate background call, with the Primary LLM as fallback
• use deterministic request parsing if the formatter is unavailable
• inject only active tasks into the owning NPC's context
• show task status and history directly below Middle Term Memory in the CHIM NPC editor
• show an in-game [CHIM] Task created for <NPC>: <task> notification after persistence succeeds

Runtime behavior

• the dialogue request queues task creation without blocking the current response
• the background service formats and persists the task, then queues the in-game confirmation
• repeating tasks advance from their original schedule anchor when completed or failed
• missed repeating intervals advance to the next future occurrence
• cancellation permanently stops recurrence
• overdue tasks remain active until resolved or cancelled
• this does not autonomously execute NPC behavior; tasks guide later dialogue, actions, and Background Life context

Validation

• PHP syntax checks passed for every changed PHP file
• focused task suite: 12 tests, 56 assertions
• live PostgreSQL creation and recurrence workflow verified
• live in-game test created task #7 for Danica Pure-Spring
• CHIM consumed and processed DebugNotification@Task created for Danica Pure-Spring: Check the town gate
• merged current unstable; PR reports cleanly mergeable
• deployed locally; migration completed, npc_commitments exists, Apache is healthy, and changed-file hashes match
• no DLL, PEX, or ESP artifacts

Scope

• HerikaServer only
• no CHIM plugin source change or rebuild is required