API Builder V1: Source picker v2 (grouped/search/recent/introspection)

[nicdavidson]

Goal
Reduce dropdown fatigue and improve source discovery speed.

Scope

• Group services by type (Database, REST, RWS, Scripted, etc.)
• Searchable source/resource picker
• Recent source chips
• Introspection badges: schema / api_docs fallback / no metadata

Acceptance Criteria

• Common source select path in <=2 interactions
• Clear fallback message when introspection is unavailable

[nicdavidson]

Resumed #496 and completed the Source Picker v2 scope on branch feature/add-api-builder.

Completed:

• Added recent source chips for one-click re-selection.
• Added resource/table search input to reduce picker scrolling.
• Kept grouped/searchable source API picker and introspection badges.
• Clarified introspection badge labels:
  • schema
  • api_docs
  • no metadata
• Added explicit fallback hint text in the UI for metadata source:
  • native schema loaded
  • api_docs fallback in use
  • no metadata available for this source type

Commit:

• 1bdf6bd feat(api-builder): complete source picker v2 with recent chips and fallback hints

Validation:

• npm run build passes (existing repo-wide warnings only).

No push yet.