feat(log): log the inputs each plan uses as "Replay input:" lines, so a log can be replayed exactly

[chalfontchubby]

Opened by Claude on Rik's behalf. Draft: the base of a stack; the forward log replay (#5363) builds on it.

Summary

A debug yaml captures one moment. Replaying the log that follows it (#5363) needs the values each later plan started from, which the human-readable log lines round or leave out. This adds Replay input: log lines carrying them exactly. None of it changes what Predbat plans or does.

Each line reads back exactly (repr floats, or dicts that ast.literal_eval reads), and inputs that rarely change are logged only when they change. Tariff comparison runs (save=False / publish=False) log none of it, as their inputs are not the live plan's.

Line	When	Content
PV forecast changed	on change	p50/p10/p90 per minute to the end of the forecast, as runs of [kWh, minutes]
load from HH:MM base X Wh, Wh/5min [...]	every cycle	the two values per 5-minute step the plan reads, as whole tenths of a Wh; falls back to full cumulative kWh for a forecast not in whole tenths
ML load forecast changed	on change	Load ML predictions as read from the sensor
rates changed	on change	import/export and their base rates from now, as change points
state	every cycle	SoC, SoC max, in-day adjustment, cost so far, day counters, charge/discharge rate in force, battery temperature, iBoost used today, load_forecast_only
cars changed, inverter changed	on change	the car state and the inverter's programmed state the plan reads
load forecast empty	on change	the forecast became empty, so the plan uses load history alone
load divergence	every plan	the divergence exactly as the plan uses it (None when off)
dynamic load baseline	on change	the load floor dynamic_load() sets for a high-load cycle (usually {})

Safety

• Every logger catches its own errors, and a value that cannot be logged warns once per change, not every cycle. The on-change lines share one helper, log_replay_changed.
• No secrets are logged.

Measured on a live system (Sigenergy, IOG, 5-6 Oct 2026)

• The replay lines are about 5% of the log. The load line, at 3.8 KB a cycle, is most of that; the compact encoding halved it. All 195,640 values in an overnight log rebuild bit for bit.
• With these lines, an exact replay of the night matched every adopted and candidate plan, and every plan metric including the base, across car dispatches and midnight (details in test(replay): replay a Predbat log forwards from a debug yaml - exact and simulated, with a plan timeline #5363).

Changes

• apps/predbat/fetch.py: the loggers and the shared on-change helper; PV and ML logging gated on save.
• apps/predbat/plan.py: the load divergence and dynamic load baseline lines, gated on publish.
• apps/predbat/predbat.py: logs the plan's starting state and the inverter state each cycle.
• apps/predbat/tests/test_log_replay_inputs.py (new), registered in unit_test.py.

Test plan

• ./run_all (full suite) and pre-commit pass.
• Deployed on Rik's system since 6 Oct; the lines are read back by the replay in test(replay): replay a Predbat log forwards from a debug yaml - exact and simulated, with a plan timeline #5363.

🤖 Generated with Claude Code

[Copilot]

🟡 Changes recommended

Empty forecasts, dynamic-load baselines, and current iBoost usage are not captured, preventing exact replay in supported runtime scenarios.

3 open findings

• Record empty forecasts to preserve exact replay · New
• Include iboost_today in replay state · New
• Log dynamic load baseline for exact replay · New

What changed in this PR

Adds exact Replay input: logging to support deterministic forward plan replay.

Changes:

• Logs forecasts, rates, runtime state, cars, inverter state, and load divergence.
• Suppresses replay logging during tariff comparisons.
• Adds comprehensive logger tests and test registration.

File	Description
apps/​predbat/​fetch.py	Implements replay-input serialization and logging hooks.
apps/​predbat/​plan.py	Logs exact load divergence.
apps/​predbat/​predbat.py	Logs plan-start and inverter state.
apps/​predbat/​tests/​test_log_replay_inputs.py	Tests serialization, change detection, and error handling.
apps/​predbat/​unit_test.py	Registers the new test suite.

🧠 Review effort: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.