Summary

Move the Design Thinking collection from experimental to preview maturity, signaling that the ecosystem's core features are complete while acknowledging it may still have rough edges.

Motivation

The Design Thinking ecosystem includes 50+ artifacts (agents, prompts, instructions, curriculum modules) that have stabilized through active use. The experimental label no longer reflects the actual maturity of the content. Graduating to preview communicates to users that:

• Core features are complete and functional
• The content is suitable for adoption with the understanding that refinements may follow
• Items remain in the PreRelease extension channel (no channel change)

Changes Required

1. Collection manifests — maturity value updates

• collections/design-thinking.collection.yml — Change collection-level maturity and all ~50 item-level maturity values from experimental to preview
• collections/hve-core-all.collection.yml — Change all design-thinking item maturity values from experimental to preview

2. Collection description

• collections/design-thinking.collection.md — Update language referencing experimental status to reflect preview

3. Plugin README banner (code gap)

• scripts/plugins/Modules/PluginHelpers.psm1 — Add an elseif branch for preview maturity in New-PluginReadmeContent to generate a preview banner (currently only experimental is handled)

4. Regenerate plugin outputs

• Run npm run plugin:generate and npm run plugin:validate to update generated files under plugins/

What already works (no changes needed)

The preview maturity level is already supported by:

• JSON Schema (collection-manifest.schema.json) — preview is in the enum
• Collection validation (Validate-Collections.ps1) — preview is in $allowedMaturities
• Extension packaging (Prepare-Extension.ps1) — handles preview correctly
• Plugin generation (Generate-Plugins.ps1) — includes preview in PreRelease channel

Acceptance Criteria

• design-thinking.collection.yml collection-level and all items set to maturity: preview
• hve-core-all.collection.yml design-thinking items set to maturity: preview
• design-thinking.collection.md description updated
• PluginHelpers.psm1 generates a preview banner for preview maturity collections
• npm run plugin:generate succeeds and plugins/design-thinking/README.md shows preview banner
• npm run plugin:validate passes
• npm run lint:all passes