feat: add architectural decision records

[gemmadanks]

What changes did you make (give an overview)?

• Added:
  • a template for creating ADRs
  • an index of ADRs
  • ADR-001 on using ADRs
• Changed
  • Updated README to point to ADRs
  • Updated docs site navigation to add Architecture pages
  • Updated PR template with a check for ADRs

Prerequisites checklist

Please check each of the following before merging:

• I have updated any relevant documentation
• I have added unit tests for any new code
• I have linked to any relevant issues
• I will squash my commits and, where needed, edit the commit messages to make them more informative follow the conventional commits format
• This pull request is ready to merge (leave unchecked to indicate a WIP)

What is the purpose of this pull request?

Check all that apply:

• Documentation update
• Bug fix
• New feature
• Changes to an existing feature
• Refactor
• Increasing test coverage
• Other, please explain:

[Copilot]

Pull Request Overview

This pull request adds comprehensive support for Architectural Decision Records (ADRs) to document design decisions for future developers and AI assistants.

• Adds ADR template, index, and first ADR explaining the rationale for using ADRs
• Updates documentation structure to include architecture section with ADR navigation
• Updates README to reference ADR documentation and includes ADR consideration in development workflow

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
mkdocs.yml	Adds Architecture navigation section with ADR template, index, and first ADR
docs/architecture/adr/template.md	Provides comprehensive template for creating future ADRs with decision matrix evaluation
docs/architecture/adr/index.md	Creates index table listing all ADRs with status and summary
docs/architecture/adr/001-use-architectural-decision-records.md	Documents the decision to adopt ADRs with detailed rationale and implementation approach
README.md	Updates project description and documentation to reference ADR support and includes ADR check in development workflow

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

docs/architecture/adr/001-use-architectural-decision-records.md:1

• Inconsistent indentation in the directory tree structure. Line 137 uses extra spaces before the pipe character, breaking the visual alignment of the tree structure.

# ADR-0001: Use Architectural Decision Records

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[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

docs/architecture/adr/template.md:1

• The indentation is inconsistent in the directory tree structure. Line 136 uses 4 spaces while line 137-139 use 8 spaces, but they should align at the same level as subdirectories of 'architecture'.

# ADR-NNN: short title for solved problem and found solution

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