chore: bump to v2.5.15 for release

Dependency movement only; no public API, signature, or wire format change,
so this is a patch bump. Release notes belong in the GitHub Release body at
tag time.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: vvillait88

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "agentscore-commerce"
-version = "2.5.14"
+version = "2.5.15"
 description = "Agentic commerce SDK for Python: identity middleware (FastAPI, Flask, Django, AIOHTTP, Sanic, ASGI) + payment helpers + 402 builders + discovery + Stripe multichain. The full merchant-side toolkit for AgentScore-powered agentic commerce."
 readme = "README.md"
 license = "MIT"