feat(provider): runnable affect-server entrypoint + ratatoskr-provider script

Stand-up glue for the live affect negotiation smoke vs Worldtree v0.35.2.

- ratatoskr.provider.serve: build_app_from_env (tested env->app seam) + main
  (uvicorn shell). Config from env: RATATOSKR_HEIMDALL_KEY (required),
  RATATOSKR_AFFECT_DB, RATATOSKR_CONSUMER_ID, RATATOSKR_PROVIDER_HOST/PORT.
- console-script ratatoskr-provider = ratatoskr.provider.serve:main.
- Heimdall key utf-8-encoded into HS256 key_bytes; revisit if Worldtree signs
  with base64/raw bytes (confirm format at wire-up).

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.17.1"
+version = "0.17.2"
 description = "Worldtree Conversation API debug TUI — multi-pane observability dashboard"
 readme = "README.md"
 requires-python = ">=3.12"
@@ -45,8 +45,9 @@ dev = [
 ]
 
 [project.scripts]
-ratatoskr     = "ratatoskr.cli:main"
-ratatoskr-web = "ratatoskr.web.entrypoint:main"
+ratatoskr          = "ratatoskr.cli:main"
+ratatoskr-web      = "ratatoskr.web.entrypoint:main"
+ratatoskr-provider = "ratatoskr.provider.serve:main"
 
 [project.urls]
 Repository = "https://gitea.phasefinal.com/vh/ratatoskr"