refactor: nuke legacy harness, drop sdk_ prefixes

The SDK harness is the only path now; legacy host-side code is gone.
File names no longer carry the ``sdk_`` distinction.

Deleted legacy host-side modules:
- strix/agents/StrixAgent/ (template moved to strix/agents/prompts/)
- strix/agents/base_agent.py, state.py
- strix/llm/llm.py, config.py
- strix/runtime/docker_runtime.py, runtime.py
- strix/tools/executor.py, agents_graph/agents_graph_actions.py
- strix/interface/sdk_dispatch.py + the env-flag dispatch in cli.py

Renamed (drop ``sdk_`` prefix):
- strix/sdk_entry.py → strix/entry.py
- strix/agents/sdk_factory.py → strix/agents/factory.py
- strix/agents/sdk_prompt.py → strix/agents/prompt.py
- strix/tools/<x>/<x>_sdk_tool[s].py → strix/tools/<x>/tool[s].py
- strix/tools/_legacy_adapter.py → strix/tools/_state_adapter.py
- ``_legacy`` aliases inside the wrappers → ``_impl``

CLI + TUI now call ``run_strix_scan`` directly — they build the
sandbox image / sources_path locally and rely on
``session_manager.cleanup`` (called inside ``run_strix_scan``'s finally)
for teardown. Three TUI handlers that reached into legacy multi-agent
globals (``_agent_instances``, ``send_user_message_to_agent``,
``stop_agent``) are now no-ops with a TODO; reconnecting them to the
``AgentMessageBus`` is a follow-up.

Tracer.get_total_llm_stats no longer reaches into the deleted
``agents_graph_actions`` globals — the orchestration hooks now feed the
tracer via ``Tracer.record_llm_usage`` (live + completed buckets).
finish_scan's ``_check_active_agents`` and load_skill's runtime
``_agent_instances`` reach-in are no-op stubs; the
``AgentMessageBus`` is the source of truth post-migration.

llm/utils.py rewritten to keep only the streaming-parser helpers
(``normalize_tool_format``, ``parse_tool_invocations``,
``fix_incomplete_tool_call``, ``format_tool_call``, ``clean_content``).
``STRIX_MODEL_MAP`` moved to ``llm/multi_provider_setup.py`` (its only
remaining caller).

Per-file ruff ignores added for legacy interface modules (TUI / main /
CLI / utils / streaming_parser / tool_components) and tracer.py —
pre-existing PLC0415/BLE001/PLR0915 patterns are out of scope.

Tests: 287/287 passing. Renamed test files to drop ``sdk_`` prefix.
``test_tracer.py::test_get_total_llm_stats_aggregates_live_and_completed``
rewritten to feed ``Tracer.record_llm_usage`` instead of legacy globals.
Test file annotations added so pre-commit's strict mypy passes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

strix/tools/file_edit/tools.py

@@ -0,0 +1,109 @@
+"""SDK function-tool wrappers for the legacy ``file_edit`` tools.
+
+These three tools (``str_replace_editor``, ``list_files``, ``search_files``)
+operate on files inside the sandbox container's ``/workspace`` filesystem.
+The legacy harness marks them ``sandbox_execution=True`` (default) so the
+executor POSTs them to the in-container tool server.
+
+The host-side SDK wrappers therefore delegate to ``post_to_sandbox`` —
+the legacy implementations live in the container image and we don't
+import them on the host (they pull in ``openhands_aci``, which is a
+sandbox-only dependency).
+"""
+
+from __future__ import annotations
+
+import json
+from typing import Any
+
+from agents import RunContextWrapper
+
+from strix.tools._decorator import strix_tool
+from strix.tools._sandbox_dispatch import post_to_sandbox
+
+
+def _dump(result: dict[str, Any]) -> str:
+    return json.dumps(result, ensure_ascii=False, default=str)
+
+
+@strix_tool(timeout=180)
+async def str_replace_editor(
+    ctx: RunContextWrapper,
+    command: str,
+    path: str,
+    file_text: str | None = None,
+    view_range: list[int] | None = None,
+    old_str: str | None = None,
+    new_str: str | None = None,
+    insert_line: int | None = None,
+) -> str:
+    """View, create, or edit a file in the sandbox.
+
+    Args:
+        command: One of ``"view" | "create" | "str_replace" | "insert" |
+            "undo_edit"``.
+        path: File path. Relative paths are anchored at ``/workspace``.
+        file_text: Required for ``create``.
+        view_range: Optional ``[start, end]`` line range for ``view``.
+        old_str / new_str: Required for ``str_replace``.
+        insert_line: Required for ``insert``.
+    """
+    return _dump(
+        await post_to_sandbox(
+            ctx,
+            "str_replace_editor",
+            {
+                "command": command,
+                "path": path,
+                "file_text": file_text,
+                "view_range": view_range,
+                "old_str": old_str,
+                "new_str": new_str,
+                "insert_line": insert_line,
+            },
+        ),
+    )
+
+
+@strix_tool(timeout=120)
+async def list_files(
+    ctx: RunContextWrapper,
+    path: str,
+    recursive: bool = False,
+) -> str:
+    """List files and directories under a sandbox path.
+
+    Args:
+        path: Directory path, relative paths anchored at ``/workspace``.
+        recursive: When True, walks subdirectories (capped at 500 entries).
+    """
+    return _dump(
+        await post_to_sandbox(
+            ctx,
+            "list_files",
+            {"path": path, "recursive": recursive},
+        ),
+    )
+
+
+@strix_tool(timeout=120)
+async def search_files(
+    ctx: RunContextWrapper,
+    path: str,
+    regex: str,
+    file_pattern: str = "*",
+) -> str:
+    """Recursively grep files in the sandbox using ripgrep.
+
+    Args:
+        path: Root path to search; relative paths anchored at ``/workspace``.
+        regex: Pattern to match (passed straight to ``rg``).
+        file_pattern: Glob filter (e.g. ``"*.py"``). Defaults to all files.
+    """
+    return _dump(
+        await post_to_sandbox(
+            ctx,
+            "search_files",
+            {"path": path, "regex": regex, "file_pattern": file_pattern},
+        ),
+    )