fix: review fixes — stale refs, skill counts, and validation guidance

- Fix -plan.md → -beta-plan.md in ce:plan-beta post-generation question
- Remove stale brainstorm doc reference from solutions doc
- Update plugin.json and marketplace.json skill counts (42 → 44)
- Add generic beta skill validation guidance to AGENTS.md and solutions doc

plugins/compound-engineering/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "compound-engineering",
   "version": "2.41.0",
-  "description": "AI-powered development tools. 29 agents, 42 skills, 1 MCP server for code review, research, design, and workflow automation.",
+  "description": "AI-powered development tools. 29 agents, 44 skills, 1 MCP server for code review, research, design, and workflow automation.",
   "author": {
     "name": "Kieran Klaassen",
     "email": "kieran@every.to",

plugins/compound-engineering/AGENTS.md

@@ -131,6 +131,14 @@ See `docs/solutions/skill-design/beta-skills-framework.md` for the full pattern.
 - Beta plan output files use `-beta-plan.md` suffix to avoid clobbering stable plan files
 - Beta skills are not wired into `lfg`/`slfg` orchestration — invoke them directly
 
+### Beta Skill Validation
+
+After creating or modifying a beta skill, search its SKILL.md for any reference to the stable skill name it replaces. Occurrences of the stable name without `-beta` are missed renames that would cause output collisions or misrouting. Check for:
+
+- Output file paths using the stable naming convention instead of the `-beta` variant
+- Cross-skill references pointing to stable names instead of beta counterparts
+- User-facing text (questions, confirmations) mentioning stable paths or names
+
 ### Promoting Beta to Stable
 
 When replacing a stable skill with its beta version:

plugins/compound-engineering/skills/ce-plan-beta/SKILL.md

@@ -511,7 +511,7 @@ Plan written to docs/plans/[filename]
 
 After writing the plan file, present the options using the platform's blocking question tool when available (see Interaction Method). Otherwise present numbered options in chat and wait for the user's reply before proceeding.
 
-**Question:** "Plan ready at `docs/plans/YYYY-MM-DD-NNN-<type>-<name>-plan.md`. What would you like to do next?"
+**Question:** "Plan ready at `docs/plans/YYYY-MM-DD-NNN-<type>-<name>-beta-plan.md`. What would you like to do next?"
 
 **Options:**
 1. **Open plan in editor** - Open the plan file for review