refactor: delete orphaned dirs, dead streaming infra, unused session/compressor

Orphaned files/dirs:
- ``strix/agents/StrixAgent/`` — empty, only ``__pycache__``.
- ``strix/tools/browser/litellm/`` — empty, only ``__pycache__``.
- ``strix/strix_runs/`` — runtime output left in the working tree.
- ``strix/prompts/`` — single Jinja template that nothing renders.

Dead streaming pipeline (was never wired in the SDK migration):
- Delete ``strix/interface/streaming_parser.py`` (XML tool-call parser
  for an output format the SDK doesn't produce).
- Strip ``streaming_content`` / ``interrupted_content`` dicts and
  five unused methods from ``Tracer``.
- Strip the streaming-render path + ``interrupted`` branch from TUI.
- Trim ``strix/llm/utils.py``: drop ``normalize_tool_format``,
  ``parse_tool_invocations``, ``format_tool_call``,
  ``fix_incomplete_tool_call`` and the XML-stripping in
  ``clean_content``. Keep only the inter-agent-XML scrub.

Unwired session compression:
- Delete ``strix/llm/strix_session.py`` and
  ``strix/llm/memory_compressor.py``. ``Runner.run`` was never called
  with a ``session=``, so the compressor never ran. Drop the matching
  test file and the ``strix_memory_compressor_timeout`` config knob.

Tracer cleanup:
- Remove ``log_agent_creation``, ``log_tool_execution_start``,
  ``update_tool_execution``, ``update_agent_status``,
  ``get_agent_tools`` — none had production callers.
- Rewrite the redaction + correlation tests against
  ``log_chat_message`` (which still emits events).

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

strix/config/config.py

@@ -17,7 +17,6 @@ class Config:
     ollama_api_base = None
     strix_reasoning_effort = "high"
     strix_llm_max_retries = "5"
-    strix_memory_compressor_timeout = "30"
     llm_timeout = "300"
     _LLM_CANONICAL_NAMES = (
         "strix_llm",
@@ -28,7 +27,6 @@ class Config:
         "ollama_api_base",
         "strix_reasoning_effort",
         "strix_llm_max_retries",
-        "strix_memory_compressor_timeout",
         "llm_timeout",
     )