Fix 30 KB errors: ExaCS storage 3-10x wrong, ECPU transition, IOPS limits, missing shapes

Cross-referenced all 70+ KB files against official Oracle docs. Critical fixes:
- ExaCS: storage was flash cache not usable disk (76.8→190.8 TB QR), added X11M, removed X10M
- ADB-S: OCPU→ECPU migration, 26ai as default, cross-region RTO 15→10 min
- Compute: E5 max 94→126, A2 80→78, added E6/A4/BM shapes, 11 GPU shapes
- Storage: Higher Perf IOPS 35K→50K, UHP 450K→300K, File Storage 25K→50K
- DBCS: E5.Flex max 94→64, storage 80→150 TB, added 26ai
- Networking: FastConnect +400 Gbps, NSG max 120 rules

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

kb/services/exacs.yaml

@@ -27,15 +27,18 @@ limits:
     - name: "Exadata.Quarter3.100"
       base_ocpu: 100
       max_ocpu: 100
-      storage_tb: 49.5
+      storage_tb: 149
+      notes: "Legacy X8 fixed shape — storage is usable disk"
     - name: "Exadata.Half3.200"
       base_ocpu: 200
       max_ocpu: 200
-      storage_tb: 99
+      storage_tb: 299
+      notes: "Legacy X8 fixed shape"
     - name: "Exadata.Full3.400"
       base_ocpu: 400
       max_ocpu: 400
-      storage_tb: 198
+      storage_tb: 598
+      notes: "Legacy X8 fixed shape; current generation is elastic X9M/X11M"
   max_vm_clusters: 8
   max_databases_per_cluster: "Limited by resources"
   max_pdb_per_cdb: 252