feat(P01-04-03,P01-04-04): wire store into pipeline + per-session cost logging
server/cost.py — derive_cost() counts LLM input/output tokens (gemma4 +
deepseek-v4-flash), Deepgram audio minutes, Cartesia/Piper characters;
derives estimated cents from scenarios/cost_rates.yaml. No enforced ceiling
(D-012 pilot). CostBreakdown dataclass carries the breakdown dict stored in
sessions.cost_breakdown_json. Per G-005: v0.1 logged costs are pilot-config
(Ollama tier + cloud), NOT at-scale /learner economics — that requires
self-hosted gemma4:e4b + Piper (post-pilot).
server/session_recorder.py — SessionRecorder wires the SQLite store into the
pipeline lifecycle: start() creates a session row, log_turn() writes turns
with ASR/TTS text + latency + accumulates cost inputs, set_branch_path(),
end() derives cost + writes outcome + debrief + updates progress. No auth —
learner_id is the hardcoded learner-1 (D-007).
7 tests pass (derive_cost basic/piper-zero/breakdown-dict, load_rates yaml,
no-enforced-ceiling, recorder full lifecycle with DB assertions, progress
updated).
---ci---
phase: 1
milestone: v0.1
plan: 04
task: 04-03,04-04
status: execute
persona: backend-engineer,data-engineer
requirements:
covered: [REQ-STATE-01, REQ-NFR-COST-01]
---/ci---
Praxis CI
376fddf18e