Parent

Part of #3000.

Goal

Add the first, low-risk memory diagnostic entry point: /doctor memory should emit a compact baseline report that users can paste into OOM / long-session memory reports before attempting heavier heap snapshots.

Scope

• Add /doctor memory command wiring.
• Report Node/V8 process memory fields:
  • rss
  • heapTotal
  • heapUsed
  • external
  • arrayBuffers
• Report V8 heap statistics / heap-space summary when available.
• Report active handle/request counts when available.
• Report platform metadata useful for triage: Node version, platform, arch, pid, uptime.
• Keep output human-readable and safe to paste in GitHub issues.

Non-goals for this first step

• No heap snapshot generation yet.
• No filesystem export yet.
• No memory timeline/ring buffer yet.
• No UI history/tool-result offload changes yet.

Follow-up slices

1. /doctor memory --export to write diagnostics.json.
2. /doctor memory --heap / hidden /heapdump, writing diagnostics first and heap snapshot second.
3. Memory pressure sampling/timeline.
4. UI history and large tool-result retention limits.

Acceptance criteria

• /doctor memory works in the interactive CLI.
• Unit tests cover the command processor path and assert key sections/fields are present.
• The command does not require optional native dependencies and degrades gracefully if V8/handle internals are unavailable.