feat: PoC - V3 space-scoped Experience API paths for CF-Entities

[khaalid subaan (Khaalidsub)]

Summary

Proof of concept demonstrating the Optimization SDK calling the Experience API via V3 space-scoped paths instead of V2 organization-scoped paths. This enables the SDK to consume audiences and experiences stored as CF-Entities rather than legacy content type entries.

Changes

SDK Patch (packages/universal/api-client/)

Replaces V2 URL construction with V3:

- v2/organizations/${clientId}/environments/${environment}/profiles
+ v3/spaces/${clientId}/environments/${environment}/profiles

For the PoC, clientId is repurposed as spaceId for V3 routing.

New Implementation (implementations/cf-entities-poc/)

Minimal React app that:

• Initializes the Optimization SDK with clientId = spaceId (iyqlttzomqet)
• Points to the dev Experience API (https://experience.ninetailed.engineering/)
• Provides buttons to send identify and page events
• Displays the raw API response showing audience evaluation and experience resolution
• Shows which experiences/variants were selected

How to test

cd implementations/cf-entities-poc
pnpm install
pnpm dev
# Open http://localhost:3002

Click "Identify (Segment User traits)" to send an identify event with traits that match the "Segment User" audience. The Experience API will:

1. Read config from KV (iyqlttzomqet:main) - populated by the config pusher in ninetailed-new PR #7111
2. Evaluate the "Segment User" audience rules against the profile
3. Return the "[Segment] Most Frequent Product Upsell" experience assignment

Companion PRs

• Entity definitions: contentful/cf-entities#feat/p13n-audiences-experiences
• Integration API + Config Pusher: ninetailed-new#7111

Architecture

React App (this PR)
    |
    v  POST /v3/spaces/iyqlttzomqet/environments/main/profiles
Experience API Gateway (dev)
    |
    v  Reads config from KV
SPACE_ENV_CONFIGS_KV["iyqlttzomqet:main"]
    |   (populated by config pusher from ninetailed-new)
    v
Profiles Durable Object
    |  Evaluates audience rules against profile
    |  Resolves experience assignments
    v
Response: { profile, experiences, changes }