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/lib/solar-snapshot

@@ -0,0 +1,97 @@
+#!/usr/bin/env bash
+# solar-snapshot — capture the latest retained/published value of every MQTT
+# topic matching a filter, over a short listen window, and print a clean table.
+#
+# Why a listen window: powermon/eg4-battery STATE topics are NOT retained — they
+# are republished every poll cycle (GS ~5s, packs ~one cycle, EVSE on-change).
+# So we subscribe for a few seconds and keep the last value seen per topic.
+# (HA discovery `.../config` topics ARE retained and show up immediately.)
+#
+# Broker credentials are read from ~/.config/powermon/powermon.yaml (the same
+# source the openevse + lvx-control tools use) so nothing is hardcoded here.
+#
+# NOTE on MQTT wildcards: `+` matches exactly ONE whole level, so it cannot be
+# used as a name prefix. `homeassistant/sensor/lifepower4_+/state` matches NOTHING.
+# To grab a family of entities, subscribe to the level wildcard and filter with -g:
+#   solar-snapshot -g lifepower4 'homeassistant/sensor/+/state'
+#
+# Usage:
+#   solar-snapshot [-w SECONDS] [-f] [-g GREP_RE] TOPIC_FILTER [TOPIC_FILTER ...]
+#     -w SECONDS   listen window (default 12)
+#     -f           print full topic path (default: strip homeassistant/<class>/ prefix)
+#     -g GREP_RE   keep only topics whose path matches this extended-regex
+#
+# Examples:
+#   solar-snapshot -g 'lvx6048_1' 'homeassistant/sensor/+/state'
+#   solar-snapshot -w 18 -g 'lifepower4_[1-6]_soc' 'homeassistant/sensor/+/state'
+#   solar-snapshot 'openevse/#'
+#   solar-snapshot -w 6 'homeassistant/sensor/lvx6048_1_battery_voltage/state' \
+#                       'homeassistant/sensor/lifepower4_1_pack_voltage/state'
+#
+# Exit status reflects the formatting stage, not mosquitto_sub's benign -W
+# window-expiry code, so callers don't misread a normal capture as a failure.
+set -eu
+
+WINDOW=12
+FULL=0
+GREP_RE=""
+while getopts "w:fg:" opt; do
+  case "$opt" in
+    w) WINDOW="$OPTARG" ;;
+    f) FULL=1 ;;
+    g) GREP_RE="$OPTARG" ;;
+    *) echo "usage: solar-snapshot [-w SECONDS] [-f] [-g GREP_RE] TOPIC_FILTER..." >&2; exit 2 ;;
+  esac
+done
+shift $((OPTIND - 1))
+if [ "$#" -lt 1 ]; then
+  echo "usage: solar-snapshot [-w SECONDS] [-f] [-g GREP_RE] TOPIC_FILTER..." >&2
+  exit 2
+fi
+
+CONF="${POWERMON_CONF:-$HOME/.config/powermon/powermon.yaml}"
+if [ ! -r "$CONF" ]; then
+  echo "solar-snapshot: cannot read broker config $CONF" >&2
+  exit 1
+fi
+
+# Pull host/port/user/pass from the mqttbroker: block of powermon.yaml.
+# Keys are anchored to leading whitespace + exact key so `name:` doesn't also
+# match `username:`.
+read -r HOST PORT USER PASS < <(awk '
+  /^[^[:space:]]/           { inblk=0 }
+  /^mqttbroker:/            { inblk=1; next }
+  inblk && /^[[:space:]]+name:/     { h=$2 }
+  inblk && /^[[:space:]]+port:/     { p=$2 }
+  inblk && /^[[:space:]]+username:/ { u=$2 }
+  inblk && /^[[:space:]]+password:/ { w=$2 }
+  END { print h, (p?p:1883), u, w }
+' "$CONF")
+
+if [ -z "${HOST:-}" ]; then
+  echo "solar-snapshot: no mqttbroker.name found in $CONF" >&2
+  exit 1
+fi
+
+# Build -t args from filters.
+TARGS=()
+for f in "$@"; do TARGS+=(-t "$f"); done
+
+# Subscribe for the window, then reduce to last-value-per-topic.
+timeout "$((WINDOW + 2))" mosquitto_sub -h "$HOST" -p "$PORT" -u "$USER" -P "$PASS" \
+  -W "$WINDOW" -v "${TARGS[@]}" 2>/dev/null \
+| { [ -n "$GREP_RE" ] && grep -E "$GREP_RE" || cat; } \
+| awk -v full="$FULL" '
+  { t=$1; $1=""; sub(/^ /,""); v=$0; last[t]=v; order[t]=NR }
+  END {
+    n=0
+    for (t in last) { keys[n++]=t }
+    # stable-ish sort by topic name
+    for (i=0;i<n;i++) for (j=i+1;j<n;j++) if (keys[j]<keys[i]) { tmp=keys[i];keys[i]=keys[j];keys[j]=tmp }
+    for (i=0;i<n;i++) {
+      t=keys[i]; disp=t
+      if (!full) { sub(/^homeassistant\/[^/]+\//,"",disp); sub(/\/state$/,"",disp) }
+      printf "%-44s %s\n", disp, last[t]
+    }
+    if (n==0) print "(no messages in window — topics idle, broker unreachable, or filter wrong)"
+  }'