refactor(composition): unify capability bindings and cleanup ownership (#8441)

Bind typed service creation, observed availability and retryable cleanup in one composition owner. Reuse selected CLI/MCP factories and canonical contract groups without copying provider operation inventories.

Closes #8429. Refs #740.

Validated paired real application workflows, actual local Codex CLI Terra/high use, complete Evidence and Unknown checkpoint parity, compiler-backed import boundaries, SDK schemas and final real mixed routing. Automated review findings were fixed at their producing owners. Existing exact-base CodeQL alerts are documented on the PR under the owner-authorized unrelated-check exception; no global alerts or security rules were changed.

Assisted-by: Suika (gensokyo-skills:suika-scatter-gather-planning)

src/python/PythonPycProviderIdentity.ts

@@ -0,0 +1,6 @@
+/** Bundled reader identity. Header python_version is a separate observed mapping. */
+export const PYTHON_PYC_PROVIDER_IDENTITY = {
+  id: "rea-python-pyc",
+  name: "REA CPython pyc parser",
+  version: "1",
+} as const;