Adds an independent assessment step to /mach10:issue-plan-review. A new Step 4 delegates to a general-purpose subagent that classifies each plan-review finding as Genuine, Nitpick, False positive, or Deferred with a brief justification. Findings now carry stable F<n>/S<n> identifiers (mirroring /mach10:pr-review), and the revised-plan and decision-comment logic keys off the new classifications.
Syncs the corresponding CLAUDE.md entries, updates the README command table, and bumps the plugin version to 1.33.0.
Fixes #147.