* fix(chat): stabilize system prompt, sequence memory extraction, send stable session id to preserve KV cache
Fixes#2927. As diagnosed in the issue, three things in Odysseus's request
pattern actively destroyed local backends' (llama.cpp / LM Studio) KV-cache
continuity, forcing a full prompt re-evaluation (15-30s+) on every turn:
1. Dynamic content folded into the system prompt every turn. Both the chat
preface (ChatProcessor.build_context_preface) and the agent system prompt
(_build_system_prompt) injected current_datetime_prompt() — text that
changes every minute — directly into system-role messages, which llm_core
then concatenates into the single system message sent as the cached
prefix. Any byte difference there invalidates the entire cache. Moved this
to a new current_datetime_context_message() helper that returns a
standalone user-role message, inserted near the end of the array (right
before the latest user turn) instead of mixed into the system prompt. The
static system prefix (preset prompt + safety policy + agent base prompt)
now stays byte-identical across turns of the same session.
2. Memory/skill extraction side-requests competed with the main completion.
run_post_response_tasks fired extract_and_store / maybe_extract_skill via
asyncio.create_task — fire-and-forget coroutines that could overlap the
next turn's main request and steal llama.cpp's limited processing slots,
evicting the cached checkpoint. They're now queued through a new
_run_extraction_jobs_sequentially helper that waits for the session's
stream to go idle and runs the jobs strictly one at a time.
3. No stable session identifier was sent to local backends, so llama.cpp
assigned a new processing slot via LRU every turn ("session_id=<empty>
server-selected (LCP/LRU)"), losing slot affinity. Added
_apply_local_cache_affinity() in llm_core, which sets session_id and
cache_prompt: true on outgoing payloads — gated to self-hosted
OpenAI-compatible endpoints only (never api.openai.com or other cloud
providers, which reject unrecognized request fields with a 400). Threaded
session_id through stream_llm / llm_call_async / stream_agent_loop from
the existing Odysseus session id.
Tests in tests/test_kv_cache_invalidation_2927.py exercise the real payload-
assembly and scheduling code paths: byte-identical system prefix across two
turns of the same session (with a regression check that genuinely changed
instructions DO still change it), the dynamic time block landing as a
user-role message, extraction jobs waiting for the stream to go idle and
running sequentially, and the outgoing payload carrying a stable session_id
(same across turns of one session, different across sessions) only for
self-hosted endpoints. Updated tests/test_user_time.py for the new message
placement.
* fix(tests): accept owner= kwarg in normalize_model_id monkeypatch
The upstream normalize_model_id signature now takes an owner= keyword
argument, and chat_helpers.py passes owner=getattr(sess, "owner", None)
at the call site. Update the test stub lambda to **kwargs so it handles
the new argument without breaking, and update chat_helpers.py to forward
the owner parameter consistently.
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Co-authored-by: Alexandre Teixeira <111787685+alteixeira20@users.noreply.github.com>
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