Diagram generation: ref-arch-driven procedure + spec validator + KB enrichment

The diagram path now follows a documented standard procedure (lookup
the closest Oracle Architecture Center reference → confirm components
→ author absolute_layout → spec validator → render → visually verify)
and ships persistent guardrails so layout regressions can't recur.

Persistent procedure changes (apply to all users, all sessions):
- tools/diagram_spec_validator.py — geometry checks (CONTAINER_TOO_THIN,
  CONTAINER_PADDING_VIOLATION, LABEL_OVERFLOW_PARENT) run BEFORE either
  renderer (drawio + PPTX). Catches the subnet-collapse / label-overflow
  bugs that the post-render drawio validator missed.
- tools/oci_diagram_gen.py + tools/oci_pptx_diagram_gen.py — call the
  spec validator before emitting any output. Adds mysql / mysql_heatwave
  type aliases.
- tools/archcenter_pattern_lookup.py — scores against cached page
  descriptions (not just the 1-line summary), supports --queries for
  multi-fragment composition, and applies synonym expansion via
  kb/architecture-center/synonyms.yaml so "LB HA cross AD" matches
  "load balancer high availability availability domain".
- kb/architecture-center/synonyms.yaml — canonical synonym table
  (load balancer, autonomous database, data guard, …) used by the
  lookup scorer.

KB enrichment:
- tools/archcenter_description_fetcher.py + 121 cached _description.md
  under kb/diagram/assets/archcenter-refs/<slug>/. Removes the runtime
  dependency on docs.oracle.com when authoring specs and feeds the
  pattern-lookup scorer.
- 110+ cached .drawio / .svg / .png references for offline reuse,
  plus the OCI Toolkit v24.2 import (kb/diagram/assets/oci-toolkit-drawio).

Documentation:
- docs/skill/output-formats.md — new "Standard diagram-generation
  procedure (MANDATORY)" + geometry rules + the new validator entry.
- SKILL.md option 2 — references the mandatory procedure.
- README.md — describes the spec validator, archcenter_pattern_lookup
  and description fetcher, and updates the KB-health table.

Tooling that backs the procedure (cumulative across recent sessions):
tools/archcenter_case_runner.py, archcenter_batch_driver.py,
archcenter_zip_downloader.py, drawio_visual_validator.py,
drawio_fidelity_eval.py, harvest_drawio_icon.py, import_oci_library.py,
oci_pptx_diagram_gen.py, oci_pptx_render.py, refresh_pptx_icon_index.py.

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

kb/diagram/assets/archcenter-refs/connect-azure-kube-with-oracle/_description.md

@@ -0,0 +1,202 @@
+# Connect Azure Kubernetes with Oracle Exadata Database Service on Oracle Database at Azure
+
+- Source: https://docs.oracle.com/en/solutions/connect-azure-kube-with-oracle/index.html
+- Date: 2025-02
+- Type: reference-architecture
+- Services: exacs, azure, oke
+- Tags: application, multicloud, azure, database
+
+## Summary (catalog)
+
+AKS workloads connecting to ExaCS on Database@Azure. Network connectivity via VNet peering, connection pooling with Oracle Universal Connection Pool for Kubernetes pod scaling.
+
+## Architecture (fetched from source)
+
+Architecture
+
+ 
+
+ 
+
+ The architecture shows a containerized application deployed in Azure
+ Kubernetes Service (AKS) and Oracle Exadata Database
+ Service in a Microsoft Azure Region with automatic backups going to Oracle Database Autonomous
+ Recovery Service in the Azure Region or OCI Object Storage in the OCI Region. 
+ 
+ 
+
+ 
+Kubernetes is a portable, extensible, open source platform for managing
+ containerized workloads and services, that facilitates both declarative configuration
+ and automation. Kubernetes is considered a cornerstone technology for cloud native
+ computing and has a large, rapidly growing ecosystem. Kubernetes services, support, and
+ tools are widely available.
+
+ 
+In this architecture a containerized application in AKS is in its own
+ application subnet. A Kubernetes cluster can contain multiple pods, each connecting to
+ its own respective Oracle Pluggable Database (PDB). The PDBs in the primary database are
+ deployed on Oracle Database@Azure that runs on Oracle Exadata Database Service on Dedicated
+ Infrastructure in an Azure Availability Zone. The container images are stored in the Azure container
+ registry. Users access the application externally through a public load balancer. 
+ 
+
+ 
+Cloud automation simplifies most lifecycle and management tasks for Oracle
+ Exadata Infrastructure and Oracle multitenant databases (CDBs and PDBs). For example,
+ adding servers and scaling OCPUs up and down, creating databases and database homes,
+ scheduling infrastructure maintenance, updating and upgrading the VM operating system,
+ Grid Infrastructure, and databases, performing backup and recovery operations, and even
+ enabling disaster recovery protections through Oracle Data Guard . 
+ 
+
+ 
+The following diagram illustrates this reference architecture.
+ 
+ Description of the illustration azure-kube-exadata-db.png 
+ azure-kube-exadata-db-oracle.zip 
+
+ 
+The architecture has the following components:
+
+ 
+ 
+- Regions 
+An Oracle Cloud
+ Infrastructure region is a localized geographic area that contains one or more data centers,
+ called availability domains. Regions are independent of other regions, and vast
+ distances can separate them (across countries or even continents).
+ 
+
+ 
+An Azure region is a geographical area in which one or more physical Azure data centers, called availability zones, reside. Regions are independent of
+ other regions, and vast distances can separate them (across countries or even
+ continents).
+ 
+
+ 
+ Azure and OCI regions are localized geographic areas. For Oracle Database@Azure , an Azure region is connected to an OCI region, with availability zones (AZs) in Azure connected to availability domains (ADs) in OCI. Azure and OCI region pairs are selected to minimize distance and latency.
+ 
+
+ 
+ 
+- Azure availability zone 
+An availability zone is a
+ physically separate data center within a region that is designed to be available
+ and fault tolerant. Availability zones are close enough to have low-latency
+ connections to other availability zones.
+
+ 
+Subnet delegation is
+ Microsoft's ability to inject a managed service, specifically a
+ platform-as-a-service service, directly into your virtual network.
+
+ 
+ 
+- Microsoft Azure Virtual Network 
+Microsoft Azure Virtual Network (VNet) is
+ the fundamental building block for your private network in
+ Azure. VNet enables many types of Azure resources, such as
+ Azure virtual machines (VM), to securely communicate with
+ each other, the internet, and on-premises networks.
+
+ 
+Subnet delegation is Microsoft's ability to inject
+ a managed service, specifically a platform-as-a-service service, directly into
+ your virtual network.
+
+ 
+ 
+- Exadata Database Service on Dedicated
+ Infrastructure 
+ Oracle Exadata Database
+ Service delivers proven Oracle Database capabilities on purpose-built, optimized Oracle Exadata Cloud Infrastructure in the public cloud. Built-in cloud automation, elastic resource scaling,
+ security, and fast performance for OLTP, in-memory analytics, and converged
+ Oracle Database workloads help simplify management and reduce costs.
+ 
+
+ 
+ Oracle Exadata Cloud Infrastructure brings more CPU cores, increased storage, and a faster network fabric to the
+ public cloud. Oracle Exadata storage servers include Exadata RDMA Memory
+ (XRMEM), creating an additional tier of storage, boosting overall system
+ performance. Exadata combines XRMEM with innovative RDMA algorithms that bypass
+ the network and I/O stack, eliminating expensive CPU interrupts and context
+ switches.
+ 
+
+ 
+ Oracle Exadata Cloud Infrastructure increases the throughput of its 100 Gbps active-active Remote Direct Memory
+ Access over Converged Ethernet (RoCE) internal network fabric, providing a
+ faster interconnect than previous generations with extremely low-latency between
+ all compute and storage servers.
+ 
+
+ 
+ 
+- Oracle Database Autonomous
+ Recovery Service 
+ Oracle Database Autonomous
+ Recovery Service is a fully managed service designed to protect Oracle Databases from data
+ loss and cyber threats. It offers faster backups with reduced database overhead,
+ reliable recovery with validated backups, and real-time protection enabling
+ recovery to within less than a second of an outage or ransomware attack. This
+ service provides a centralized data protection dashboard and is recommended for
+ backing up Oracle Databases.
+ 
+
+ 
+ 
+- Azure Kubernetes Services 
+Azure Kubernetes Service
+ (AKS) is a managed Kubernetes service offered by Microsoft Azure to deploy and
+ manage containerized applications. A Kubernetes cluster can contain multiple
+ pods.
+
+ 
+ 
+- Oracle Database@Azure 
+ Oracle Database@Azure is the Oracle Database service ( Oracle Exadata Database Service on Dedicated
+ Infrastructure and Oracle Autonomous Database Serverless ) running on Oracle Cloud Infrastructure (OCI), deployed in Microsoft Azure
+ data centers. The service offers features and price parity with OCI, users
+ purchase the service on Azure Marketplace.
+ 
+
+ 
+ Oracle Database@Azure integrates Oracle Exadata Database
+ Service , Oracle Real Application Clusters (Oracle
+ RAC) , and Oracle Data Guard technologies into the Azure platform. Users manage the service on the Azure
+ console and with Azure automation tools. The service is deployed in Azure
+ Virtual Network (VNet) and integrated with the Azure identity and access
+ management system. The OCI and Oracle Database generic metrics and audit logs
+ are natively available in Azure. The service requires users to have an Azure
+ subscription and an OCI tenancy. Oracle Autonomous Database is built on Oracle Exadata Cloud Infrastructure , is self-managing, self-securing, and self-repairing, helping eliminate
+ manual database management and human errors. Autonomous Database enables development of scalable AI-powered apps with any data using built-in
+ AI capabilities using your choice of large language model (LLM) and deployment
+ location.
+ 
+
+ 
+Both Oracle Exadata Database
+ Service and Oracle Autonomous Database Serverless are easily provisioned through the native Azure Portal, enabling access to
+ the broader Azure ecosystem.
+ 
+
+ 
+Customer commercial benefits
+ include using Azure commitments (MACC) for procuring Oracle Exadata Database
+ Service , OCI Object Storage and Oracle Cloud Infrastructure
+ Networking Data Transfer fees. It is possible to leverage existing Oracle licenses as
+ BYOL as well as license included, a collaborative support model and procurement
+ in Microsoft Azure Marketplace, all presented as one unified
+ bill.
+ 
+
+ 
+ 
+- Control Plane 
+A Kubernetes control plane manages the resources for the worker nodes and pods within a Kubernetes cluster. The control plane components detect and respond to events, perform scheduling, and move cluster resources.
+
+ 
+ 
+- Object storage 
+ OCI Object Storage provides quick access to large amounts of structured and unstructured data of any content type, including database backups, analytic data, and rich content such as images and videos. You can safely and securely store data dire

kb/diagram/assets/archcenter-refs/connect-azure-kube-with-oracle/readme.txt

@@ -0,0 +1,7 @@
+The diagram you downloaded is available in these formats:
+- DRAWIO
+- SVG
+
+You can customize them for your organization using the associated tools:
+- For DRAWIO format, use draw.io for Confluence, online at diagrams.net, or the desktop app. Go to diagrams.net for more information.
+- For SVG format, use an SVG editor such as Inkscape or Sketsa SVG Editor, which are free and available for Windows, macOS, Linux.