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/learn-about-maa-for-peoplesoft/_description.md

@@ -0,0 +1,111 @@
+# Learn about maximum availability architecture for PeopleSoft
+
+- Source: https://docs.oracle.com/en/solutions/learn-about-maa-for-peoplesoft/index.html
+- Date: 2024-08
+- Type: reference-architecture
+- Services: exacs, adg, load-balancer, compute
+- Tags: application, ha-dr, peoplesoft
+
+## Summary (catalog)
+
+MAA for PeopleSoft on OCI. Active Data Guard for database HA/DR, multi-instance PIA behind Load Balancer, Process Scheduler on multiple nodes for batch processing resilience.
+
+## Architecture (fetched from source)
+
+Architecture
+
+ 
+
+ 
+The following architecture diagrams show PeopleSoft and Oracle
+ Maximum Availability Architecture (Oracle MAA). 
+
+ 
+PeopleSoft Maximum Availability Architecture is a PeopleSoft high
+ availability architecture layered on top of the Oracle Database and Oracle Fusion
+ Middleware Oracle MAA, including a secondary site to provide business continuity in the
+ event of a primary site failure.
+
+ 
+The following shows a full-stack Oracle MAA architecture, including primary
+ and secondary sites. The secondary site is a replica of the primary. 
+ 
+ Description of the illustration peoplesoft-maa-arch.png 
+
+ peoplesoft-maa-arch-oracle.zip 
+ 
+ 
+
+ 
+Each site consists of the following:
+
+ 
+ 
+- An HTTPS load balancer for web-based application services 
+ 
+- Two servers that host the PeopleSoft Pure Internet Architecture (PIA)
+ domain 
+ 
+- Two servers that host both the PeopleSoft Application Server and the
+ Process Scheduler domains 
+ 
+- A shared file system for PeopleSoft application software and report
+ repository 
+ 
+- An Oracle Real Application Clusters (Oracle
+ RAC) database, with two database servers and shared storage
+ 
+ 
+- Oracle Active Data Guard , which allows routing of “mostly read operations” to the standby database while
+ keeping the standby database current with the primary
+ 
+ 
+ 
+Both the application tier shared file system and the database are replicated
+ to the secondary site – the application tier using rsync, and the database tier using
+ Oracle Data Guard .
+ 
+
+ 
+The data at the second site is kept in sync with the primary by using
+ appropriate replication mechanisms.
+
+ 
+ 
+- For the database itself, Oracle Active Data Guard ensures the standby database is kept in sync and transactionally consistent.
+ 
+ 
+- For file system output generated during the operation of the
+ application, rsync is used to frequently replicate the output to
+ another region. There will be a small gap to resolve by identifying missing file
+ system components and determining the action to take for each.
+ 
+ 
+ 
+
+ 
+
+ 
+
+ 
+
+ 
+
+ 
+ Title and Copyright Information 
+
+ 
+
+ 
+Learn about maximum availability architecture for PeopleSoft
+
+ 
+F87909-01
+
+ 
+August 2024
+
+ 
+ Copyright © 2024, 
+
+Oracle and/or its affiliates.