perf: avoid continuous port scans when the inspector is closed

[jasonsuhari]

Problem

GridBash launches platform socket inspection and builds a full process snapshot every two seconds even when the port inspector is closed. Multiple GridBash instances amplify this background process and CPU overhead.

Acceptance checks

• Opening or manually refreshing the inspector produces a fresh scan.
• Closed-inspector background work is eliminated or reduced to a low-cost, clearly bounded cadence.
• A hung platform command cannot leave refresh permanently stuck.
• Existing port attribution and terminate-before-reverify behavior remains covered.