fix: add disable-model-invocation to beta skills and refine descriptions

Beta skills now use disable-model-invocation: true to prevent accidental
auto-triggering. Descriptions written as future stable descriptions with
[BETA] prefix for clean promotion. Updated solutions doc and AGENTS.md
promotion checklist to include removing the field.

plugins/compound-engineering/AGENTS.md

@@ -125,6 +125,8 @@ See `docs/solutions/skill-design/beta-skills-framework.md` for the full pattern.
 ### Beta Skill Rules
 
 - Beta skills use `-beta` suffix in directory name, skill name, and description prefix (`[BETA]`)
+- Beta skills set `disable-model-invocation: true` to prevent accidental auto-triggering — users invoke them manually
+- Beta skill descriptions should be the intended stable description prefixed with `[BETA]`, so promotion is a simple prefix removal
 - Beta skills must reference other beta skills by their beta names (e.g., `/deepen-plan-beta`, not `/deepen-plan`)
 - 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
@@ -135,6 +137,7 @@ When replacing a stable skill with its beta version:
 
 - [ ] Replace stable `SKILL.md` content with beta skill content
 - [ ] Restore stable frontmatter: remove `[BETA]` prefix from description, restore stable `name:` (e.g., `ce:plan` not `ce:plan-beta`)
+- [ ] Remove `disable-model-invocation: true` so the model can auto-trigger the skill
 - [ ] Update all internal references back to stable names (`/deepen-plan` not `/deepen-plan-beta`)
 - [ ] Restore stable plan file naming (remove `-beta` from `-beta-plan.md` convention)
 - [ ] Delete the beta skill directory

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

@@ -1,7 +1,8 @@
 ---
 name: ce:plan-beta
-description: "[BETA] Transform feature descriptions or requirements into structured, decision-first implementation plans. Use when testing the new planning workflow. Produces plans focused on decisions, boundaries, and verification rather than pre-written implementation choreography."
+description: "[BETA] Transform feature descriptions or requirements into structured implementation plans grounded in repo patterns and research. Use when the user says 'plan this', 'create a plan', 'write a tech plan', 'plan the implementation', 'how should we build', 'what's the approach for', 'break this down', or when a brainstorm/requirements document is ready for technical planning. Best when requirements are at least roughly defined; for exploratory or ambiguous requests, prefer ce:brainstorm first."
 argument-hint: "[feature description, requirements doc path, or improvement idea]"
+disable-model-invocation: true
 ---
 
 # Create Technical Plan

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

@@ -1,7 +1,8 @@
 ---
 name: deepen-plan-beta
-description: "[BETA] Stress-test an existing implementation plan and selectively strengthen weak sections with targeted research. Use when a plan from ce:plan-beta needs more confidence around decisions, sequencing, system-wide impact, risks, or verification."
+description: "[BETA] Stress-test an existing implementation plan and selectively strengthen weak sections with targeted research. Use when a plan needs more confidence around decisions, sequencing, system-wide impact, risks, or verification. Best for Standard or Deep plans, or high-risk topics such as auth, payments, migrations, external APIs, and security. For structural or clarity improvements, prefer document-review instead."
 argument-hint: "[path to plan file]"
+disable-model-invocation: true
 ---
 
 # Deepen Plan