add dolibarr-thirdparty-completeness and dolibarr-tva-deductible

V4 bundle — two more sibling skills, both read-only, both depending
on the dolibarr base skill.

dolibarr-thirdparty-completeness:
- audit-thirdparty.sh <socid>: country-aware completeness audit for
  any thirdparty (FR: SIREN + SIRET + tva_intra; EU non-FR: tva_intra;
  extra-EU: national tax id). Generalizes the V1 KM-hardcoded script.
- audit-all-thirdparties.sh: loops over /thirdparties and surfaces a
  compact table of gaps. --clients-only / --suppliers-only flags.
- Live baseline finds 5/10 thirdparties with mandatory gaps:
  KissMetrics (US tax id), Wise Europe SA (BE tva_intra), Medialex
  (FR SIRET + tva_intra), Qonto (SIRET), Infogreffe (SIRET).

dolibarr-tva-deductible:
- deductible-by-month.sh: TVA déductible aggregated per period × rate.
- deductible-line-detail.sh: per supplier-invoice line with country-
  based CA3 bucket assignment (ligne 20 for 20 % FR, ligne 19 for
  reduced rates, ligne 17+24 for intra-UE autoliquidation).
- Live baseline: 223.22 € total TVA déductible across 13 lines.
  Wise Europe SA correctly identified as intra-UE autoliquidation;
  La Poste correctly identified as FR exempt (timbres).
- Mirrors dolibarr-tva-reconciliation on the supplier side. Together
  they give the two numbers a CA3 monthly declaration needs.

Also extends dolibarr/SKILL.md endpoint catalogue with /supplierinvoices
(noting the 403 on the /lines sub-endpoint — inline lines on the detail
endpoint make this a non-issue). dolibarr/README.md gains two new
permission checkboxes for Factures fournisseurs.

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

.claude/skills/dolibarr/examples/acl_403_supplier_lines.json

@@ -0,0 +1,16 @@
+{
+    "_captured_when": "2026-05-29 — ai_agent permission baseline. Lines come through inline on /supplierinvoices/{id} so this 403 is informational only and doesn't block any current workflow. If a future skill needs the dedicated /lines endpoint, ai_agent needs an additional permission grant.",
+    "_curl": "curl -H 'DOLAPIKEY: <key>' https://erp.arcodange.lab/api/index.php/supplierinvoices/1/lines",
+    "_http_status": 403,
+    "error": {
+        "code": 403,
+        "message": "Forbidden"
+    },
+    "debug": {
+        "source": "api_supplier_invoices.class.php:614 at call stage",
+        "stages": {
+            "success": ["get", "route", "negotiate", "authenticate", "validate"],
+            "failure": ["call", "message"]
+        }
+    }
+}