fix(optimizer): retain legal future EV charging headroom

[frahlg]

The worker could exclude a legal future EV charging step from its planning reserve and charge earlier at a higher price. The updated worker keeps that step available while retaining grid limits, actual charger pulses and departure goals.

Pin the compiled workers from private source commit 38c4872a5f646e0b822f7645ae06f3b454a8ffea (srcfl/energyplan#77), for Energyplan v0.5.2-beta.2. The worker handshake remains 0.5.2 and both protocols remain v1. The bundle contains Linux ARM64, Linux AMD64 and macOS ARM64 executables, with their complete licenses, notices and checksum manifest.

Validation:

• All 22 private local CI stages passed on that exact clean source commit: Rust and vendored solver tests, crash and malformed-input checks, pulse/stress/rolling checks, 60 Core-shaped requests, independent HiGHS/SCIP references, advisory audit, minimum Rust checks and both Linux packages.
• Both Linux executables and all shared bundle files match the full local CI packages byte for byte. Core's bundle verifier checks the manifest, executable architectures, hashes, license files, host handshake and public source boundary.
• make native-solver-test and full make verify passed with the replacement bundle. The separate fix(mpc): keep valid plans when forecast caution fails #1644 Core fixes also passed whole MPC, forecast and entrypoint race suites against this exact worker.
• An independent audit passed nine before/after cases and 18 real calls using the packaged release worker. It checks stored Wh, deadlines, instantaneous joint charging pulses, negative prices, a partly elapsed first interval, two EVs and unreachable targets. The simple price case changes from 21 SEK to 10.50 SEK with the same delivered energy; this is synthetic evidence, not measured customer savings.

The separate PV-independent intermediate reserve preference remains and can still favor earlier charging over a cheaper PV-dependent schedule. This update removes the extra headroom margin; it does not claim the cheapest schedule under physics alone. Core's guard that retains a valid point plan when optional forecast caution fails is separate in #1644.

Private worker release: https://github.com/srcfl/energyplan/releases/tag/v0.5.2-beta.2.

A standalone run of the exact Linux ARM64 artifact on homelab-rpi passed three synthetic cases: a cheap legal later step, one watt too little headroom, and a genuinely unreachable goal with a 1000 Wh shortfall. A separate Wh, power and cost replay passed. The run issued no hardware commands and did not update the running Core.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-15T18:40:56.271637Z	424f790	PR opened

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