fix(runtime-e2e): verify unknown default + drop stale merge-status note (#2912)

[gzak]

Summary

Follow-up to #218 (merged). axonflow-enterprise#2953 (caller_name) has since merged to axonflow-enterprise main and shipped in platform v9.11.0. That merge also folded in #2903, which changed the fallback default written to policy_details.caller_name when neither caller_name nor tool_type is supplied from "claude_code" to "unknown" — an unidentified caller must never be silently attributed to a specific client.

• runtime-e2e/caller_name_audit/test.py — adds a third real-stack scenario: neither field supplied → policy_details.caller_name == "unknown" (not "claude_code").
• runtime-e2e/caller_name_audit/README.md — replaces the stale "axonflow-enterprise#2953 is an open PR, not yet merged" prerequisite note (true when feat(client): add caller_name to audit_tool_call (#2912) #218 merged, no longer true) with the current v9.11.0 platform requirement, and documents the third scenario.

No SDK code changes. caller_name and tool_type were already independently settable fields on AuditToolCallRequest (see #218), so unlike the plugin repos (codex-plugin#82, cursor-plugin#83, openclaw-plugin#156) this SDK never needed a "dual-send" cutover — callers could already send both together, and the existing unit test test_caller_name_and_tool_type_together already covers it.

Implements getaxonflow/axonflow-enterprise#2912, sub-issue of epic #2905.

Test plan

• runtime-e2e/caller_name_audit/test.py rerun against a freshly built axonflow-enterprise main (commit 7a5984ec7+, platform v9.11.0, docker compose build from source, not a stale/cached image) — all three scenarios pass:

  PASS: policy_details.caller_name = 'e2e-caller-name-probe-<run>' reached the audit_logs row via the real agent+orchestrator stack
  PASS: legacy tool_type='mcp' still resolves into policy_details.caller_name = 'mcp' (deprecated fallback intact)
  PASS: neither caller_name nor tool_type supplied -> policy_details.caller_name = 'unknown' (#2903 default, not 'claude_code')
  ALL PASS: caller_name (#2912) verified end-to-end through the real SDK + platform
  

• Independently confirmed via direct platform inspection (audit_logs.policy_details in Postgres, and a raw curl against /api/v1/audit/tool-call + /api/v1/audit/tenant/{id}) before landing the SDK-level assertion.
• Full unit suite: 1060 passed, 29 skipped (coverage 82.74%, threshold 75%).
• scripts/lint-no-mocks-in-runtime-e2e.sh — clean.
• ruff check — clean on touched files.

[gzak]

R3 review: clean, no findings. Independently re-ran the runtime-e2e test against the real local v9.11.0 stack — all 3 scenarios (caller_name, legacy tool_type fallback, neither-supplied → "unknown") genuinely pass. CI green. Ready to merge.