[P2.2-T03] Update log writer with governance fields

[RichardHightower]

Task: Update log writer with governance fields

Phase: 2.2 - Enhanced Logging
Estimated: 0.5 day
File: cch_cli/src/logging/writer.rs
Depends on: P2.2-T02

Description

Populate new governance fields when writing log entries.

Acceptance Criteria

• Populate new fields when writing log entries
• Include mode from matched rule
• Include priority from matched rule
• Include decision from action result
• Include metadata if present
• Add integration tests for log format

[RichardHightower]

Completed in PR #72