schema: Milestone YAML definition missing slaDuration, slaStartFrom, entryCriteria fields

[treblereel]

Problem

The Milestone Java API class (api/model/Milestone.java) supports three fields that have no corresponding entries in the YAML JSON Schema (schema/src/main/resources/schema/CaseDefinition.yaml) and are not wired in CaseDefinitionYamlMapper:

Field	Java API	YAML Schema	Mapper
slaDuration	Duration via builder	missing	not wired
slaStartFrom	SlaStartFrom enum (MILESTONE_ACTIVATED, CASE_CREATED)	missing	not wired
entryCriteria	ExpressionEvaluator via builder	missing	not wired — defaults to always-true

Currently milestone SLA tracking and entry criteria are only configurable via the Java DSL (Milestone.builder().slaDuration(...).slaStartFrom(...).entryCriteria(...)). YAML-defined cases cannot use these features.

Expected YAML

milestones:
  - name: approval
    condition: '.approved == true'
    entryCriteria: '.submitted == true'
    slaDuration: PT2H
    slaStartFrom: MILESTONE_ACTIVATED

Scope

1. Add slaDuration (ISO-8601 duration string), slaStartFrom (enum: MILESTONE_ACTIVATED | CASE_CREATED), and entryCriteria (JQ string) to the Milestone definition in CaseDefinition.yaml
2. Wire the three fields in CaseDefinitionYamlMapper.convertToApiModel() milestone conversion block
3. Add validation: slaDuration must be positive if present; slaStartFrom defaults to MILESTONE_ACTIVATED
4. Add unit tests in CaseDefinitionYamlMapperTest for the new fields
5. Add a YAML example exercising milestone SLA