Improve SKU catalog hygiene and BOM accuracy

- refresh_sku_catalog.py: add --discover to report API SKUs missing from
  catalog, filtered to already-curated serviceCategory values. Auto-runs
  at end of --validate and --refresh so gaps surface on every maintenance
  pass. First run found 162 missing SKUs (Blackwell GPUs, X12 Ax compute,
  VMware reserved tiers, WebLogic-on-OKE, Analytics/OIC BYOL).
- oci_bom_gen.py: fix Cost % column being blank. Back-fill was gated on
  formula detection but data rows write raw numbers, so the predicate
  never matched. Now tracks data_item_rows explicitly.
- .gitea/workflows/sku-catalog-refresh.yaml: monthly automation (1st at
  09:00 UTC). Auto-refresh prices → push branch + open PR; detect new
  SKUs → open issue with labels. Gated on secrets.GITEA_TOKEN.
- kb/pricing/oci-sku-catalog.yaml: add B95714 / B95715 (Autonomous ATP
  Dedicated ECPU, LI + BYOL) — canonical SKUs for ADB-D pricing.
- kb/services/compute.yaml: add X12 family (VM.Standard4.Ax.Flex,
  BM.Standard4.Ax.120), E6.Ax and A4.Ax variants. Verified against
  docs.oracle.com computeshapes.htm. Bump last_verified + changelog.
- templates/bom-spec.yaml: document 730 hrs/month convention as default
  (= real annual billing / 12; 744 overstates by 1.92% on 12-month TCO).
- Makefile: new 'make sku-discover' target.

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

tools/oci_bom_gen.py

@@ -328,6 +328,7 @@ class OCIBomGenerator:
 
         data_start_row = row
         cat_subtotal_rows = []
+        data_item_rows = []  # line-item rows (excludes category headers/subtotals/totals)
 
         # Ensure categories present in items but missing from catalog order
         # (e.g., "other" from unknown SKUs) still render at the end.
@@ -418,6 +419,7 @@ class OCIBomGenerator:
                     ws.cell(row=row, column=COL_CONV_WO).number_format = '#,##0.00'
                     ws.cell(row=row, column=COL_CONV_W).number_format = '#,##0.00'
 
+                data_item_rows.append(row)
                 row += 1
 
             # Category subtotal row
@@ -492,17 +494,15 @@ class OCIBomGenerator:
 
         # ── Cost proportion formulas (back-fill) ─────────────────
         # Cost % = line monthly w/ discount / total monthly w/ discount
-        for item_row in range(data_start_row, total_row):
-            cell_val = ws.cell(row=item_row, column=COL_M_W).value
-            if cell_val and str(cell_val).startswith("=") and "SUM" not in str(cell_val):
-                mw_l = get_column_letter(COL_M_W)
-                ws.cell(
-                    row=item_row, column=COL_PCT,
-                    value=f"=IF({mw_l}{total_row}=0,0,{mw_l}{item_row}/{mw_l}{total_row})",
-                )
-                ws.cell(row=item_row, column=COL_PCT).number_format = '0.0%'
-                ws.cell(row=item_row, column=COL_PCT).font = data_font
-                ws.cell(row=item_row, column=COL_PCT).border = thin_border
+        mw_l = get_column_letter(COL_M_W)
+        for item_row in data_item_rows:
+            ws.cell(
+                row=item_row, column=COL_PCT,
+                value=f"=IF({mw_l}{total_row}=0,0,{mw_l}{item_row}/{mw_l}{total_row})",
+            )
+            ws.cell(row=item_row, column=COL_PCT).number_format = '0.0%'
+            ws.cell(row=item_row, column=COL_PCT).font = data_font
+            ws.cell(row=item_row, column=COL_PCT).border = thin_border
 
         # ── Notes ─────────────────────────────────────────────────
         if self.notes: