[Integration][P0] Illexium — cards one-time payments

[shuklatushar226]

Integrate Illexium in hyperswitch-prism (UCS) for cards one-time payments.

Field	Value
Merchant	Illexium
Docs	Available (shared by merchant)
Credentials	Will get soon — requested
Group	Supergroup
Priority	P0
Scope	Cards one time payments
Owner	@shuklatushar226

Flows to implement

• Authorize — auto capture
• Authorize — manual capture
• Capture
• PSync
• Void / cancel
• Refund
• RSync
• Error code → GSM mapping
• Incoming webhooks for the flows above

Checklist

• Auth type + connector config defined
• Request/response transformers with unit tests
• Connector registered in the connector enum
• Sandbox config wired (development.toml / sandbox config)
• Sandbox verification for each flow above, results pasted here

Blockers

• Credentials pending. Merchant has shared docs; creds have been requested and are expected soon. Implementation can start from the docs in parallel.