Track 3: Doctor Surface (check + repair + audit)

[pikaxinge]

Context

Depends on Track 1 + Track 2.

Scope

Track 3: Doctor Surface

• T3.1 Check framework (config/dependency/filesystem/runtime)
• T3.2 Repair framework (idempotent actions, non-interactive mode)
• T3.3 Doctor CLI

File Anchors

• snapagent/doctor/checks/*.py (new)
• snapagent/doctor/repair/*.py (new)
• snapagent/cli/commands.py

Acceptance Criteria

• snapagent doctor provides diagnostic report with severities
• --repair and --repair --yes execute safe idempotent actions
• Repair actions emit auditable events