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/SKILL.md

@@ -94,6 +94,7 @@ Read-only endpoints we've validated against this instance. Live captures are und
 | `GET /thirdparties`                            | 200  | List thirdparties                    | `mode` MUST be integer (`mode=1` = customers). String fails 400. | (use `/{id}` below) |
 | `GET /thirdparties/{id}`                       | 200  | Thirdparty detail                    | KissMetrics is `id=1` in this instance                           | [thirdparty_km.json](examples/thirdparty_km.json) |
 | `GET /products` / `/products/{id}`             | 200  | Product catalogue                    | `KM-audit` is `id=1`, `KM-cloud-devops` is `id=2`                | [products_list.json](examples/products_list.json) |
+| `GET /supplierinvoices` / `/{id}`              | 200  | Supplier (fournisseur) invoices      | Lines are included inline on the detail endpoint (same shape as `/invoices/{id}`). Sub-endpoint `/lines` returns **HTTP 403** for `ai_agent` — not needed since inline lines work. | [supplierinvoices_list.json](examples/supplierinvoices_list.json) · [supplierinvoice_detail.json](examples/supplierinvoice_detail.json) |
 | `GET /invoices/templates/{id}`                 | 200  | Recurring invoice template detail    | **No list endpoint** — probe ids 1..N. Empty ids return HTTP 200 with `id=null` (sentinel for "doesn't exist"). Fields: `ref`, `socid`, `frequency`, `unit_frequency`, `nb_gen_done`, `date_when`, `date_last_gen`, `suspended`, `auto_validate`, `lines`. | [invoice_template_km.json](examples/invoice_template_km.json) |
 | `GET /documents/download`                      | 200  | Download a stored document as base64 | `modulepart=facture&original_file=<REF>/<REF>.pdf` (URL-encode slashes). Returns `{filename, content-type, filesize, content}` with `content` base64. | [document_download_meta.json](examples/document_download_meta.json) |
 
@@ -139,6 +140,8 @@ Not available on this account (intentionally): `/setup/modules` (admin-only), `/
 - Workflow skill for monthly TVA basis (CA3 / CA12 preparation): [dolibarr-tva-reconciliation](../dolibarr-tva-reconciliation/SKILL.md).
 - Workflow skill for recurring invoice templates: [dolibarr-recurring-templates](../dolibarr-recurring-templates/SKILL.md).
 - Workflow skill for point-in-time state archival: [dolibarr-data-snapshot](../dolibarr-data-snapshot/SKILL.md).
+- Workflow skill for thirdparty completeness audit (any client / supplier): [dolibarr-thirdparty-completeness](../dolibarr-thirdparty-completeness/SKILL.md).
+- Workflow skill for supplier-side TVA déductible (CA3 lignes 19 / 20 / 17+24): [dolibarr-tva-deductible](../dolibarr-tva-deductible/SKILL.md).
 - Future workflow skills follow the `dolibarr-<topic>` convention. Each one depends on this skill for connection + permissions + endpoint reference; each one keeps its triggers focused on its specific business workflow.
 
 ## Out of scope