Add SA Tools: BOM generator and AppCA export

- New tools/oci_bom_gen.py: generates .xlsx BOM from YAML spec with
    Oracle Redwood styling, Excel formulas, and Oracle disclaimer.
    Supports standard BOM (--output) and AppCA import format (--appca)
  - New tools/refresh_sku_catalog.py: refreshes SKU catalog prices from
    Oracle's public pricing API (apexapps.oracle.com)
  - New kb/pricing/oci-sku-catalog.yaml: ~160 OCI SKUs across 14
    categories, validated against Oracle API
  - New templates/bom-spec.yaml: input spec template for BOM generation
  - Add SA TOOLS section to SKILL.md (options 13-14)
  - Register BOM generator in oci_output.py

.gitignore

@@ -31,3 +31,4 @@ examples/*.yaml
 
 # Exported PDFfiles
 examples/*.pdf
+examples/*.xlsx