fix(control): include EV load in manual self consumption

[frahlg]

Summary

• Make Self (manual) drive its PI from the raw site meter, including positive EV charging even when battery_covers_ev is off.
• Keep the existing EV policy in other modes and keep V2X discharge excluded by default.
• Keep surplus-only loadpoints from using the home battery for EV charging while still allowing the battery to cover house load.
• Add a patch changeset and update the affected golden control cases.

Root cause

Self (manual) subtracted EV charging from the site-meter signal. With PV charging the home battery and a larger EV load making the full site import, the PI saw house-side export and could ask the battery to charge harder. That looked and behaved like battery charging while the site imported.

Self (manual) now follows the normal self-consumption rule: drive the full site meter toward zero.

Safety

Fuse, SoC, slew, stale-meter and V2X guards are unchanged. The surplus-only cap still prevents home-battery discharge into its EV.

Validation

• Björn's reported case: 5.56 kW site import, 4.26 kW battery charge and 8.11 kW EV load converges toward a -1.3 kW battery target and zero site flow.
• go test -count=1 ./internal/drivers ./internal/control
• make verify
• Pre-push make verify-all, including Linux arm64, Linux amd64 and Windows amd64 builds.

Overlap

The patch was developed against #769, then replayed as one commit on current master; no #769 changes are included. It also applies cleanly with the open #887 and #888 control patches.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Scope the discharge floor to surplus-only EV power

When a site has both a surplus-only loadpoint and a regular loadpoint, EVSurplusOnlyReserveW is activated only by the former, but this calculation subtracts the aggregate EVChargingW from every live charger. For example, with a 3 kW surplus-only EV, a 4 kW regular EV, 1 kW house load, and BatteryCoversEV=true, the new floor limits the battery to -1 kW instead of allowing -5 kW to cover the house and regular EV while leaving the surplus-only EV unsupported. Track/subtract the surplus-only EV's actual draw separately so this clamp protects only the loadpoint that requires it.

AGENTS.md reference: AGENTS.md:L37-L37

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