feat(skills,cli): supplier avoirs + banque lire (bank-account discovery)

The two V9 follow-ups, both proven live on the sandbox.

- creditnote-create.sh: `kind:"supplier"` makes an avoir fournisseur on
  /supplierinvoices (type=2 + fk_facture_source, carries ref_supplier); default
  customer path unchanged. Proven: customer AVC002 (-240) + supplier AVF2026001
  (-144, ref_supplier carried, linked to source, validated).
- bank-accounts.sh + `arcodange sandbox accounts`: list bank accounts (id/label/
  bank) so a payment can pick its account_id. Needs `banque lire` (rights 111),
  now added to the provisioner's WRITE_IDS so fresh runs include it; the existing
  ai_agent_sandbox user was granted it live. GET /bankaccounts now returns the 3
  accounts (QONTO, WISE EURO, Compte Courant Asso).
- SKILL.md: supplier-avoir example + accounts helper + updated banque-lire note.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/skills/dolibarr-sandbox-write/scripts/creditnote-create.sh

@@ -1,16 +1,20 @@
 #!/usr/bin/env bash
-# Create a customer credit note (avoir) in the SANDBOX — a customer invoice of
-# type 2 that references the original invoice. Amounts come out negative.
+# Create a credit note (avoir) in the SANDBOX — an invoice of type 2 that
+# references the original invoice. Amounts come out negative. Customer avoir =
+# /invoices; supplier avoir (avoir fournisseur) = /supplierinvoices.
 #
 # Input: a JSON object on stdin (or a file path in $1):
-#   socid          (required) the client (must match the source invoice's client)
+#   socid          (required) the third party (must match the source invoice's)
 #   source_invoice (required) the original invoice id being credited
+#   kind           "customer" (default) | "supplier"
+#   ref_supplier   (supplier only) the supplier's avoir reference (recommended —
+#                  some supplier setups require it to validate)
 #   date           "YYYY-MM-DD"  (default today)
 #   validate       true|false    (default false = leave draft)
 #   lines: [ { desc, qty, price_ht, tva, type: "product"|"service", product_id? } ]
 #          the lines being credited (positive amounts; Dolibarr nets them as a credit)
 #
-# Emits {id, ref, total_ht, total_ttc, fk_facture_source, statut} on stdout.
+# Emits {id, ref, ref_supplier, total_ht, total_ttc, fk_facture_source, statut}.
 set -euo pipefail
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 W="${DOL_WRITE:-${SCRIPT_DIR}/dol-write.sh}"
@@ -25,6 +29,7 @@ d = json.loads(sys.stdin.read())
 for req in ("socid", "source_invoice"):
     if not d.get(req):
         sys.exit("creditnote-create.sh: '%s' is required" % req)
+is_supplier = str(d.get("kind", "customer")).lower() in ("supplier", "fournisseur")
 ds = d.get("date")
 epoch = int((datetime.datetime.strptime(ds, "%Y-%m-%d") if ds
              else datetime.datetime.now()).timestamp())
@@ -43,22 +48,26 @@ for ln in d.get("lines", []):
     lines.append(L)
 body = {"socid": d["socid"], "type": 2, "fk_facture_source": d["source_invoice"],
         "date": epoch, "lines": lines}
+if is_supplier and d.get("ref_supplier"):
+    body["ref_supplier"] = d["ref_supplier"]
 print(json.dumps(body))
 print("1" if d.get("validate") else "0")
+print("/supplierinvoices" if is_supplier else "/invoices")
 PY
 
 MAPPED="$(printf '%s' "${INPUT}" | python3 "${PYF}")"
 BODY="$(sed -n 1p <<<"${MAPPED}")"
 VALIDATE="$(sed -n 2p <<<"${MAPPED}")"
+ENDPOINT="$(sed -n 3p <<<"${MAPPED}")"
 
-ID="$("${W}" POST /invoices "${BODY}")"
+ID="$("${W}" POST "${ENDPOINT}" "${BODY}")"
 if [[ ! "${ID}" =~ ^[0-9]+$ ]]; then
   echo "creditnote-create.sh: create did not return an id: ${ID}" >&2
   exit 1
 fi
 if [[ "${VALIDATE}" == "1" ]]; then
-  "${W}" POST "/invoices/${ID}/validate" '{}' >/dev/null
+  "${W}" POST "${ENDPOINT}/${ID}/validate" '{}' >/dev/null
 fi
-"${W}" GET "/invoices/${ID}" | python3 -c "import json,sys
+"${W}" GET "${ENDPOINT}/${ID}" | python3 -c "import json,sys
 d=json.load(sys.stdin)
-print(json.dumps({k:d.get(k) for k in ('id','ref','total_ht','total_ttc','fk_facture_source','statut')}))"
+print(json.dumps({k:d.get(k) for k in ('id','ref','ref_supplier','total_ht','total_ttc','fk_facture_source','statut')}))"