feat: add local participant and session identifiers

[SuzukiKatsuma]

Summary

Adds identifiers for associating operation logs with a local participant and a recording session.

Changes

• Add persistent local_participant_id configuration at %APPDATA%\operation-logger\config.json
• Add local_participant_id and per-session session_id to session_metadata.json
• Display the full local_participant_id in both GUI and CLI
• Back up invalid local participant config files before regenerating them

Motivation

The logger is distributed as a common GitHub Release binary, so participant-specific IDs cannot be embedded at distribution time.

This change allows each local Windows user environment to keep a stable local_participant_id, while each recording session receives a separate session_id for grouping logs during analysis.

local_participant_id is used instead of user_id because the identifier represents a locally stored participant identifier, not necessarily a globally unique person.

Notes

• CSV schemas are unchanged.
• Log directory names are unchanged.
• session_id is stored only in session_metadata.json.