doc: update documentation for ontology-driven architecture

[JessUWE]

This PR updates the ACRO documentation to reflect the new ontology-driven architecture introduced. The changes explain how ACRO's disclosure checking has moved from hard-coded logic to an ontology-driven approach, making it more maintainable, auditable, and extensible.

Changes

New Files

• docs/source/user_guide/architecture.rst - Detailed technical architecture reference for developers and TRE administrators
  • Explains the four JSON knowledge files (analyses.json, statbarns.json, risks.json, checks.json)
  • Documents core classes: SDCChecks, TableModelDetails, SDCEvidence, ChecksResults, ManyChecksResults
  • Details suppression via data redaction and category preservation
  • Covers federated evidence serialisation
  • Guides adding new analysis types

Updated Files

API Documentation

• docs/source/api.rst - Enhanced with new sections on ontology-driven checking classes (SDCChecks, SDCEvidence, ChecksResults, ManyChecksResults, TableModelDetails)
• docs/source/api/acro_class.rst - Expanded with complete method documentation including mitigation control methods (enable_suppression, disable_suppression, enable_rounding, disable_rounding)
• docs/source/api/records_class.rst - Added module-level functions and detailed class documentation

Landing Pages

• docs/source/index.rst - Updated release note highlighting ontology-driven architecture
• docs/source/introduction.rst - explanation of principles-based SDC and three-phase pipeline

User Guide

• docs/source/user_guide.rst - Improved navigation and structure with clear learning paths
• docs/source/user_guide/getting_started.rst - Beginner-friendly guide with complete workflow examples
• docs/source/user_guide/core_concepts.rst - Deep dive into SDC principles, new architecture classes, and design patterns
• docs/source/user_guide/configuration.rst - configuration guide with tables, examples, and precedence rules

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.81%. Comparing base (f4173ed) to head (fbf0ea6).
⚠️ Report is 10 commits behind head on main.

Additional details and impacted files

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+ Coverage   99.75%   99.81%   +0.05%     
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  Files          10       15       +5     
  Lines        1602     2107     +505     
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+ Hits         1598     2103     +505     
  Misses          4        4              

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[jim-smith]

a very few minor things to change/suggestions otherwise good to go. Much improved

[jim-smith]

couple of minor tweaks please.

• I'm worried that we might give the impression the safety parameters can be changed by researchers
• statbarnsdc already covers 114/5 types of analysis, and any changes to the ontology need to go through a strict approval process. So we need to make clear that we are talking about how people implement code to support functions already present in statbarnssdc