@W-23748899 feat(composition): render if/then/else conditional schemas

[alexpmule]

What

Render JSON Schema 2020-12 / OAS 3.1 if/then/else conditional schemas in api-type-document.

AMF 5.11 already parses these keywords into shacl#if / shacl#then / shacl#else triples with the branch shapes fully present, but the component had no rendering support for them. A shape whose only content was a conditional fell through to the AnyShape scalar fallback in _typeChanged and collapsed to a generic "Any" badge — the branch properties (kind / breed / indoor) were silently dropped.

Why

Follow-up to #100 (W-23748896), which added OAS 3.1 composition-label support but explicitly scoped out conditional schemas. Filed as W-23748899 under the OAS 3.1/3.2 API Console umbrella (TD-0333486).

How

• Detection (_typeChanged): a single additive check after the existing if / else-if chain flags isConditional when the shape carries the if keyword and resolves the three branch shapes. It only ever clears isScalar (gated on isConditional) and never writes any other flag, so oneOf/anyOf/allOf/object detection cannot regress.
• Raw SHACL IRIs: the frozen amf-helper-mixin namespace exposes no if/then/else members, so the IRIs are built from the existing shacl namespace prefix and passed through _getAmfKey exactly like every other shacl key in the file. No change to amf-helper-mixin.
• Rendering (_conditionalTemplate): mirrors the existing _anyTemplate/_oneOfTemplate pattern — each present branch renders via a recursive <api-type-document>, reusing the existing property/enum rendering (the if condition's const: dog surfaces through the existing shacl#in path). then and else are independently optional per JSON Schema, so an if+else shape without then renders both branches instead of a blank.

Scope

• No changes to amf-helper-mixin, TypeStyles.js, or the property-rendering components.
• Out of scope: oneOf/anyOf/allOf (unchanged), OAS 3.2-specific keywords.

Testing

New describe('Conditional type (if/then/else)') block (runs in both Regular and Compact model variants) against the existing PetKindFields fixture from demo/oas31-webhooks:

• isConditional true / isScalar false (does not collapse to "Any") — AC1
• if/then/else resolve to NodeShape branches — AC1
• branch documents render kind / breed / indoor, and the if condition shows the const value dog — AC2
• if+else-without-then renders If + Else with no silent blank — AC1 edge

Full suite: 586 passed, 0 failed, 13 skipped — oneOf/anyOf/allOf blocks unchanged (AC3).

Acceptance criteria

• AC1 — If/Then/Else branches (and their properties) render instead of collapsing to "Any"
• AC2 — demo/oas31-webhooks PetKindFields renders kind=dog (If) / breed (Then) / indoor (Else)
• AC3 — no regression to oneOf/anyOf/allOf rendering

Notes for reviewers

• Stacked on W-23748896-composition-labels (@W-23748896 feat(composition): render meaningful labels for oneOf/anyOf/allOf variants (OAS 3.1) #100) — it depends on the oas31-webhooks fixture that PR adds. Base retargets to master once @W-23748896 feat(composition): render meaningful labels for oneOf/anyOf/allOf variants (OAS 3.1) #100 merges.
• Version bump deferred to avoid a version conflict with the parent branch; will bump before merge.

Screenshots