feat(limits): honest kei limits CLI + pet cache integration

Cross-CLI subscription limits — research-grounded honest delivery after
5-parallel-agent investigation found that 4 of 5 CLIs have no public
programmatic API for quota.

## Reality findings (research)

- claude    no public API; `anthropic-ratelimit-*` headers per-call only;
            Admin API exists but needs separate admin token. See dashboard.
- grok      no public API; `x-ratelimit-*` headers per-call only. No file.
- agy       interactive /usage slash-cmd shows 100% always (forum bug).
            No public API.
- copilot   no public quota API; web dashboard only. The 'gh api /user/
            copilot_billing' endpoint does NOT exist. June 2026 billing
            migration to AI Credits further changes the surface.
- kimi      Moonshot /v1/users/me/balance returns $ balance only (no
            session/weekly quota fields). Requires MOONSHOT_API_KEY.

## Delivery (no false promises)

- scripts/kei-limits.sh — probe-all honest tool. For Kimi: real curl
  call to Moonshot balance API if MOONSHOT_API_KEY set. For other 4:
  status marker + dashboard URL.
- Pet integration — reads ~/.claude/pet/limits-cache.json IF present;
  shows Kimi balance segment ONLY when status=='live'. Pet does NOT poll;
  cache is populated by user-invoked 'kei limits'.
- bin/kei limits arm + --json mode + --quiet mode for cron.

Cache is bounded by user's explicit refresh; pet shows '(Xm old)' if
older than 1h. No background polling, no rate-limit waste, no fake data.

bin/kei

@@ -20,6 +20,8 @@
 #   kei mcp-wire [<cli>]    # wire kei-mcp into a CLI's MCP config + hook setup
 #                           # (Phase C cross-CLI policy enforcement)
 #   kei mcp-wire --list     # show enforcement tier per CLI
+#   kei limits              # probe each CLI's subscription quota (best-effort)
+#                           # (4 of 5 CLIs have no public API — honest report)
 #   kei --on=<backend>      # one-shot launch of <backend> (does not change primary)
 #   kei [args...]           # splash → exec primary CLI (default: claude)
 #
@@ -66,6 +68,10 @@ case "${1:-}" in
     shift
     exec "$HOME/.claude/scripts/kei-mcp-wire.sh" "$@"
     ;;
+  limits|quota|usage)
+    shift
+    exec "$HOME/.claude/scripts/kei-limits.sh" "$@"
+    ;;
 esac
 
 # --- one-shot --on=<backend> override (does not write primary.toml) -------

scripts/kei-limits.sh

@@ -0,0 +1,161 @@
+#!/usr/bin/env bash
+# kei-limits — probe each installed CLI's remaining quota / balance.
+#
+# Reality (research 2026-05-26):
+#   • claude  — no programmatic API. Headers per-API-call only. Admin API
+#               exists but needs a separate admin key. See dashboard.
+#   • grok    — same as claude. Headers per-API-call only. No file.
+#   • agy     — interactive /usage slash-cmd is broken (shows 100% always,
+#               forum-verified bug). No public API.
+#   • copilot — no public quota API. github.com/settings/billing only.
+#               Inline output during call shows usage but nothing exposed
+#               for poll.
+#   • kimi    — Moonshot API /v1/users/me/balance returns $ balance only
+#               (no session/weekly quota). Requires MOONSHOT_API_KEY.
+#
+# Output:
+#   stdout: human summary (default) OR JSON (--json)
+#   file:   ~/.claude/pet/limits-cache.json (always, for pet to read)
+#
+# Polling: NOT poll-friendly. Run on demand or via launchd at >5 min intervals.
+# Pet's job: read the cache; pet does NOT call this script.
+
+set -u
+
+CACHE="${KEI_LIMITS_CACHE:-$HOME/.claude/pet/limits-cache.json}"
+mkdir -p "$(dirname "$CACHE")"
+
+JSON_OUT=0
+QUIET=0
+for arg in "$@"; do
+  case "$arg" in
+    --json)  JSON_OUT=1 ;;
+    --quiet) QUIET=1 ;;
+    -h|--help) sed -n '2,22p' "$0" | sed 's|^# \{0,1\}||'; exit 0 ;;
+  esac
+done
+
+# --- per-CLI probes (each returns one JSON value to stdout) ----------------
+probe_claude() {
+  # No public API; produce a status marker, no live data.
+  printf '%s' '{"status":"no-api","note":"see claude.ai/settings/usage","dashboard":"https://claude.ai/settings/usage"}'
+}
+
+probe_grok() {
+  printf '%s' '{"status":"no-api","note":"headers-only per API call; see x.ai dashboard","dashboard":"https://x.ai"}'
+}
+
+probe_agy() {
+  printf '%s' '{"status":"broken-api","note":"interactive /usage shows 100% (forum-verified bug); use Google Cloud Console","dashboard":"https://console.cloud.google.com/apis/api/generativelanguage.googleapis.com/quotas"}'
+}
+
+probe_copilot() {
+  # Try gh CLI graphQL — most variants don't expose Copilot billing publicly.
+  # If we ever find an endpoint, drop it in here. For now: status marker.
+  printf '%s' '{"status":"no-api","note":"see github.com/settings/billing → Copilot section","dashboard":"https://github.com/settings/billing"}'
+}
+
+probe_kimi() {
+  if [ -z "${MOONSHOT_API_KEY:-}" ]; then
+    printf '%s' '{"status":"need-key","note":"set MOONSHOT_API_KEY in env to fetch live balance","dashboard":"https://platform.kimi.ai"}'
+    return
+  fi
+  # Real probe: Moonshot balance API. Honest about what we get back.
+  if ! command -v curl >/dev/null 2>&1; then
+    printf '%s' '{"status":"no-curl","note":"curl required for live probe"}'
+    return
+  fi
+  local resp
+  resp=$(curl -sS --max-time 5 \
+    -H "Authorization: Bearer $MOONSHOT_API_KEY" \
+    "https://api.moonshot.ai/v1/users/me/balance" 2>/dev/null || echo '')
+  if [ -z "$resp" ]; then
+    printf '%s' '{"status":"probe-failed","note":"no response (network / wrong key)"}'
+    return
+  fi
+  # Validate JSON shape.
+  local avail cash voucher
+  avail=$(printf '%s' "$resp" | jq -r '.data.available_balance // empty' 2>/dev/null)
+  if [ -z "$avail" ]; then
+    printf '%s' '{"status":"probe-failed","note":"API returned non-balance response"}'
+    return
+  fi
+  cash=$(printf '%s' "$resp"   | jq -r '.data.cash_balance // 0'      2>/dev/null)
+  voucher=$(printf '%s' "$resp" | jq -r '.data.voucher_balance // 0'  2>/dev/null)
+  jq -n --arg s "live" --arg a "$avail" --arg c "$cash" --arg v "$voucher" \
+    '{status:$s, available_balance_usd:($a|tonumber), cash_balance_usd:($c|tonumber), voucher_balance_usd:($v|tonumber), dashboard:"https://platform.kimi.ai"}'
+}
+
+# --- assemble cache JSON ---------------------------------------------------
+NOW=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+jq -n \
+  --arg ts "$NOW" \
+  --argjson claude  "$(probe_claude)" \
+  --argjson grok    "$(probe_grok)" \
+  --argjson agy     "$(probe_agy)" \
+  --argjson copilot "$(probe_copilot)" \
+  --argjson kimi    "$(probe_kimi)" \
+  '{ts:$ts, claude:$claude, grok:$grok, agy:$agy, copilot:$copilot, kimi:$kimi}' \
+  > "$CACHE"
+
+# --- output ----------------------------------------------------------------
+if [ "$JSON_OUT" = "1" ]; then
+  cat "$CACHE"
+  exit 0
+fi
+
+if [ "$QUIET" = "1" ]; then
+  exit 0
+fi
+
+C0= CB= CG= CY= CR= CD=
+if [ -t 1 ]; then
+  C0=$'\033[0m'
+  CB=$'\033[1;38;5;39m'
+  CG=$'\033[32m'
+  CY=$'\033[33m'
+  CR=$'\033[31m'
+  CD=$'\033[2m'
+fi
+
+format_one() {
+  local label="$1" key="$2" data="$3"
+  local status note
+  status=$(printf '%s' "$data" | jq -r '.status')
+  note=$(printf '%s' "$data" | jq -r '.note // ""')
+  case "$status" in
+    live)
+      local avail
+      avail=$(printf '%s' "$data" | jq -r '.available_balance_usd // empty')
+      printf "  ${CG}✓${C0} %-8s \$%-8s ${CD}live (Moonshot balance)${C0}\n" "$label" "$avail"
+      ;;
+    no-api|need-key)
+      printf "  ${CY}?${C0}  %-8s ${CD}%s${C0}\n" "$label" "$note"
+      ;;
+    broken-api)
+      printf "  ${CR}✗${C0} %-8s ${CD}%s${C0}\n" "$label" "$note"
+      ;;
+    *)
+      printf "  ${CY}?${C0}  %-8s ${CD}%s${C0}\n" "$label" "$note"
+      ;;
+  esac
+}
+
+cat <<EOF
+
+${CB}╔════════════════════════════════════════════════════════════╗
+║  KeiSeiKit · CLI subscription limits                         ║
+╚════════════════════════════════════════════════════════════╝${C0}
+
+EOF
+
+CACHE_CONTENT=$(cat "$CACHE")
+for cli in claude grok agy copilot kimi; do
+  data=$(printf '%s' "$CACHE_CONTENT" | jq -c ".$cli")
+  format_one "$cli" "$cli" "$data"
+done
+
+echo
+echo "${CD}cached: $CACHE${C0}"
+echo "${CD}note:   no CLI exposes session/weekly quota in a poll-friendly way.${C0}"
+echo "${CD}        See dashboards via 'open <url>' from --json output.${C0}"

scripts/keisei-pet.sh

@@ -127,6 +127,37 @@ fi
 [ -n "$spend" ] && global+="${spend} "
 global="${global% }"
 
+# v0.43: CLI subscription limits (best-effort).
+# Pet does NOT poll — reads cache only. Cache populated by `kei limits`.
+# Reality: 4 of 5 CLIs have no programmatic limit API (see research). Pet
+# shows only what's actually available + how stale the cache is.
+limits_cache="${HOME}/.claude/pet/limits-cache.json"
+limits=""
+if [ -f "$limits_cache" ]; then
+  # Cache age in seconds.
+  cache_ts=$(jq -r '.ts // empty' "$limits_cache" 2>/dev/null)
+  if [ -n "$cache_ts" ]; then
+    # Convert ISO8601 to epoch (macOS + Linux compatible).
+    cache_epoch=$(
+      date -j -u -f "%Y-%m-%dT%H:%M:%SZ" "$cache_ts" "+%s" 2>/dev/null \
+      || date -u -d "$cache_ts" "+%s" 2>/dev/null \
+      || echo 0
+    )
+    cache_age=$(( now - cache_epoch ))
+    # Kimi balance (only CLI with live API). Show $X.XX if available.
+    kimi_avail=$(jq -r '.kimi | select(.status=="live") | .available_balance_usd' "$limits_cache" 2>/dev/null)
+    if [ -n "$kimi_avail" ] && [ "$kimi_avail" != "null" ]; then
+      limits+="K:\$$(printf '%.2f' "$kimi_avail" 2>/dev/null) "
+    fi
+    # Stale marker if older than 1h.
+    if [ "$cache_age" -gt 3600 ] 2>/dev/null && [ -n "$limits" ]; then
+      stale_min=$((cache_age / 60))
+      limits="${limits% }${dim}(${stale_min}m old)${reset} "
+    fi
+  fi
+fi
+limits="${limits% }"
+
 # ── THIS session: tokens + context% (from statusLine stdin) ─────────────────
 sess=""
 if [ -n "$SLINE" ]; then
@@ -172,6 +203,7 @@ proj="${PWD##*/}"; [ -z "$proj" ] && proj="~"
 out=""
 [ -n "$sess" ]   && out+="${sess}  "
 [ -n "$global" ] && out+="${dim}${global}${reset}  "
+[ -n "$limits" ] && out+="${dim}${limits}${reset}  "
 [ -n "$plan" ]   && out+="${plan} "
 out+="${color}${face}${reset}"
 [ -n "$message" ] && out+=" ${dim}${message}${reset}"