feat(client): add caller_name to audit_tool_call (#2912)

[gzak]

Summary

• Adds caller_name to AuditToolCallRequest (axonflow/types.py) — the correctly-named replacement for tool_type, which every real caller (claude_code/codex/cursor/openclaw) actually used to identify which client made the call, not any property of the tool.
• tool_type is kept as a deprecated input fallback, not removed — backward compatible for existing callers during the deprecation window.
• client.audit_tool_call (axonflow/client.py) forwards caller_name the same way tool_type is forwarded today; docstring example and debug logging updated accordingly.
• Mirrors the platform-side resolution implemented in getaxonflow/axonflow-enterprise#2953 (open, not yet merged at the time of this PR): caller_name if supplied -> legacy tool_type if supplied -> a default. This SDK change is additive and safe to merge independently, but shouldn't be relied on in production until #2953 lands.

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

Test plan

• tests/test_audit_tool_call.py — new unit tests: caller_name sent alone, tool_type alone (backward compat), both supplied together, plus a type-level model_validate test with caller_name.
• runtime-e2e/caller_name_audit/test.py — real-stack proof (no mocks) driving the actual SDK's audit_tool_call against a live agent+orchestrator, polling GET /api/v1/audit/tenant/{tenant_id} and asserting caller_name (and the legacy tool_type fallback) reach policy_details.caller_name on the persisted audit row.
• Full unit suite: 1051 passed, 29 skipped (coverage 82.29%, threshold 75%).
• scripts/lint-no-mocks-in-runtime-e2e.sh — clean.
• ruff check — clean on all touched files.
• CHANGELOG.md [Unreleased] updated.

[gzak]

R3 review passed cleanly, but the final CI run on the pushed commit surfaced 3 real, fixable failures (final sweep before considering this done):

1. ruff format — runtime-e2e/caller_name_audit/test.py wasn't formatted. Fixed.
2. Wire-shape contract — same class of issue as the sibling Go SDK PR: caller_name is new drift not yet in tests/fixtures/wire_shape_baseline.json. Regenerated the baseline against the correctly pinned community-mirror SHA via scripts/refresh_wire_shape_baseline.py.
3. test_committed_baseline_has_no_unannotated_drift_entries — the new baseline entry needs a note classification (spec-bug-pending / deprecated-pending-removal / acknowledged-sdk-superset / sdk-aggregation). Added acknowledged-sdk-superset referencing #2912/#2953, matching the pattern used by Budget's pre-existing entry.

Full suite now green: 1051 passed, 29 skipped, 82.29% coverage.