feat: thread session_locator into flush_session_log via Protocol dispatch

Replace the direct claude_code_log_path(cwd, session_id) call in
flush_session_log with Protocol-dispatched resolution through
SessionLocator.session_log_path(). Add a session_locator kwarg with
lazy ClaudeSessionLocator() fallback to avoid import-time coupling
between session_log and the backends module.

Migration:
- 15 monkeypatch.setattr sites in test_session_log_fields.py replaced
  with explicit injection via _FakeLocator test helper
- conftest._flush() updated to accept and forward session_locator
- 2 new structural guard tests:
  - test_session_locator_is_optional_parameter (signature guard)
  - test_flush_helper_forwards_session_locator (forwarding guard)

This unblocks dispatching the cc_log resolution through any backend
that supplies a SessionLocator (Codex, future backends) without
hard-coupling to the claude module.

Author: Trecek

src/autoskillit/execution/session_log.py

@@ -16,13 +16,12 @@
 from typing import TYPE_CHECKING, Any, Literal
 
 if TYPE_CHECKING:
-    from autoskillit.core import ProviderOutcome, RecipeIdentity, SessionTelemetry
+    from autoskillit.core import ProviderOutcome, RecipeIdentity, SessionLocator, SessionTelemetry
 
 
 from autoskillit.core import (
     ModelIdentity,
     atomic_write,
-    claude_code_log_path,
     default_log_dir,
     get_logger,
     iter_merged_assistant_turns,
@@ -154,6 +153,7 @@ def flush_session_log(
     is_resume: bool = False,
     codex_log_path: Path | None = None,
     backend: Literal["claude-code", "codex"] = "claude-code",
+    session_locator: SessionLocator | None = None,
     telemetry: SessionTelemetry,
 ) -> None:
     """Flush session diagnostics to disk.
@@ -187,7 +187,13 @@ def flush_session_log(
         cc_log = None
         cc_log_str = None
     else:
-        cc_log = claude_code_log_path(cwd, session_id)
+        if session_locator is not None:
+            _locator = session_locator
+        else:
+            from autoskillit.execution.backends.claude import ClaudeSessionLocator
+
+            _locator = ClaudeSessionLocator()
+        cc_log = _locator.session_log_path(cwd, session_id)
         cc_log_str = str(cc_log) if cc_log else None
 
     if cc_log and not cc_log.exists():

tests/execution/conftest.py

@@ -310,7 +310,9 @@ def _subagent_assistant_ndjson(
     )
 
 
-def _flush(tmp_path: Path, *, backend: str = "claude-code", **overrides) -> None:
+def _flush(
+    tmp_path: Path, *, backend: str = "claude-code", session_locator=None, **overrides
+) -> None:
     from autoskillit.core.types._type_results import ModelIdentity, ProviderOutcome
     from autoskillit.core.types._type_results_execution import (
         RecipeIdentity,
@@ -393,6 +395,7 @@ def _flush(tmp_path: Path, *, backend: str = "claude-code", **overrides) -> None
         provider_outcome=provider_outcome,
         recipe_identity=recipe_identity,
         backend=backend,
+        session_locator=session_locator,
     )
 
 

tests/execution/test_flush_completeness_guard.py

@@ -56,6 +56,14 @@ def test_recipe_identity_is_required_parameter(self):
         param = sig.parameters["recipe_identity"]
         assert param.default is inspect.Parameter.empty
 
+    def test_session_locator_is_optional_parameter(self):
+        from autoskillit.execution.session_log import flush_session_log
+
+        sig = inspect.signature(flush_session_log)
+        assert "session_locator" in sig.parameters
+        param = sig.parameters["session_locator"]
+        assert param.default is None
+
 
 class TestFlushOutputCompleteness:
     """Every ProviderOutcome field must appear in flush output."""