chore(pstack): bump to 0.15.22

[poteto]

Bumps pstack from 0.15.21 to 0.15.22 in pstack/.cursor-plugin/plugin.json and pstack/plugin.json.

Covers these merged PRs, which landed without their own bumps:

• fix(pstack): let poteto-agent find poteto-mode, drop ignored frontmatter, document the / menu #597 — let poteto-agent find poteto-mode, drop ignored frontmatter, document the / menu
• feat(pstack): add /in-your-own-words to play back the goal before work #602 — add /in-your-own-words
• feat(pstack): shorten /ketchup replies and build them on real visuals #595 — shorten /ketchup replies and build them on real visuals
• feat(pstack): propose a cheap always-on signal after a deep debugging dig #604 — propose a cheap always-on signal after a deep debugging dig

Test plan

• node scripts/validate-plugins.mjs

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Note

Low Risk
Manifest-only version field updates with no runtime or behavioral code changes in this PR.

Overview
Release bump: pstack 0.15.21 → 0.15.22 in both plugin manifests (pstack/.cursor-plugin/plugin.json and pstack/plugin.json). No other files change in this diff.

This version tag rolls up work that already merged without a semver bump—poteto-agent / poteto-mode discovery and docs (#597), the /in-your-own-words command (#602), and shorter /ketchup replies with visual grounding (#595).

^{Reviewed by Cursor Bugbot for commit 7c99cdb. Bugbot is set up for automated code reviews on this repo. Configure here.}