Add solar monitoring/troubleshooting skills for agents

Four Skill-tool skills under .claude/skills/ that let an agent monitor and
troubleshoot the install (2x LVX6048, 6x EG4 LifePower4, OpenEVSE), grounded
in the real MQTT/HA topology rather than generic advice:

- solar-health-check  : whole-system sweep + cross-checks + R/Y/G verdict,
                        incl. cross-unit "silently-dead inverter" detection
- troubleshoot-inverter: FWS fault decode, parallel sync, USB link recovery
- troubleshoot-battery : per-pack imbalance vs SoC-counter-drift, RS485 silence
- power-usage         : PV/load/grid/battery balance + EVSE sessions

Shared lib:
- solar-snapshot : live MQTT capture (creds from powermon.yaml, no hardcoding)
- ha-history     : HA recorder lookback (token from ~/.config/ha/token)
REFERENCE.md documents topology, real HA entity_ids (doubled slug), known
issues, and a safe-remediation-only action policy (restarts yes; setters no).

Action boundary: diagnose + restart wedged daemons / recover USB links;
never touches inverter/battery setters or flash.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/.gitignore

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