pstack: make poteto-mode a sticky mode with a conditional reminder

[poteto]

Summary

• Adds custom-mode frontmatter to poteto-mode (mode: true, icon: crown, color: yellow, reminder:), so entering /poteto-mode persists across turns: the full skill body injects on entry, and the reminder line injects on each later turn.
• The reminder is deliberately conditional rather than "stay in mode": it gates on a task boundary, applies the skill only on a playbook match or when rigor is needed, and stands down on casual turns and explicit opt-outs — so mid-task "keep going" turns don't re-enter the mode and casual questions don't get ceremony. The wording won a 5-candidate × 4-scenario behavioral eval (blind judge, transcript-verified conduct); "stay in mode" style reminders countermand explicit opt-outs, and per-turn self-check questions induce full re-entry on continuations.
• The reminder references the skill by name (not a repo path) since pstack installs as a plugin.
• Bumps pstack to 0.10.3.

Test plan

• No internal references (grep clean)
• Enter /poteto-mode in a fresh session with pstack installed: mode pill renders (crown/yellow), reminder injects on subsequent turns

---

Note

Low Risk
Plugin skill metadata and version bump only; no runtime app logic, auth, or data handling.

Overview
Turns /poteto-mode into a sticky Cursor mode by adding custom-mode frontmatter on the skill (mode: true, icon: crown, color: yellow). After entry, the full skill still injects once; later turns get a short reminder line instead of re-injecting the whole body.

The reminder is conditional, not “always stay in mode”: re-apply /poteto-mode on a new task when a playbook matches or rigor is needed; skip on casual turns or explicit opt-out. It names the skill (/poteto-mode) for plugin installs, not a repo path.

pstack version bumps 0.10.2 → 0.10.3.

^{Reviewed by Cursor Bugbot for commit acbcd0e. Bugbot is set up for automated code reviews on this repo. Configure here.}