chore: standardize Apache Maven 3.9.15 across workflows, docs, and devcontainer

[Copilot]

Description

This updates repository-wide Maven version references from 3.9.14 to 3.9.15 to keep CI/workflow configuration, documentation, and Codespaces/devcontainer setup aligned on one Apache Maven version.

• Workflow configuration
  • Updated maven-version values to 3.9.15.
  • Updated Maven cache key/version segments from maven-3.9.14 to maven-3.9.15.
• Documentation alignment
  • Updated docs and internal guidance that referenced 3.9.14 to 3.9.15.
• Codespaces/devcontainer
  • Updated devcontainer Maven version references to 3.9.15.

Example updated pattern:

with:
  maven-version: 3.9.15

Type of Change

Primary Changes

• 🚀 New Feature
• 🔄 Enhancement
• 🐛 Bug Fix
• 📦 Dependency Update

Political Analysis

• 📊 Political Data Analysis
  • Party Analysis
  • Committee Processing
  • Government Data
  • Riksdagen Integration
• 📈 Analytics & Metrics
  • Performance Metrics
  • Risk Assessment
  • Decision Analysis
  • Transparency Metrics

Technical Changes

• 🎨 UI/UX Changes
  • Layout Updates
  • Form Improvements
  • Visualization Updates
• 🏗️ Infrastructure
  • Database Changes
  • Performance Optimization
  • Configuration Updates
• 🔒 Security & Compliance
  • Authentication
  • Authorization
  • Data Protection
• 📝 Documentation
  • Technical Documentation
  • User Documentation
  • API Documentation
• ✅ Testing
  • Unit Tests
  • Integration Tests
  • Performance Tests

Impact Analysis

Political Analysis Impact

• Impact on data quality: None.
• Impact on analysis accuracy: None.
• Impact on transparency features: None.

Technical Impact

• Performance impact: None expected at runtime; CI/devcontainer tooling version alignment only.
• Security implications: Neutral-to-positive via consistent toolchain versioning.
• Dependency changes: Apache Maven reference bumped from 3.9.14 to 3.9.15 in workflows/docs/devcontainer metadata.

Testing

• Unit tests added/updated
• Integration tests added/updated
• Political data validation completed
• Security compliance verified
• Performance testing completed

Documentation

• JavaDoc updated
• README updated
• API documentation updated
• Package/module documentation updated
• Political analysis documentation updated

Screenshots

N/A.

Related Issues

Issue linking handled by automation.

Checklist

• Code follows project coding standards
• Comments are clear and helpful
• Documentation is updated
• Tests are passing
• Security compliance is maintained
• Performance impact is acceptable
• Breaking changes are documented
• Changes are backward compatible

Additional Notes

Scope is intentionally narrow: version-string alignment only.

Security Considerations

• No sensitive data exposed
• Security best practices followed
• Compliance requirements met

Release Notes

Standardized Apache Maven version references to 3.9.15 across GitHub workflows, repository documentation, and Codespaces/devcontainer configuration.

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

Pull request overview

Updates repository references to Apache Maven 3.9.15 to keep CI workflows, documentation, and devcontainer/Codespaces configuration aligned on a single Maven version.

Changes:

• Bumped maven-version in GitHub Actions workflows to 3.9.15
• Updated Maven cache keys/docs from maven-3.9.14 to maven-3.9.15
• Updated documentation and devcontainer Maven version references to 3.9.15

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
WORKFLOWS.md	Updates workflow runtime documentation to Maven 3.9.15.
README.md	Updates development requirements table to Maven 3.9.15+.
E2ETestPlan.md	Updates E2E plan tooling table to Maven 3.9.15+.
.github/workflows/site-generation.yml	Updates cache keys and maven-version to 3.9.15.
.github/workflows/release.yml	Updates cache keys and maven-version to 3.9.15.
.github/workflows/javadoc-generation.yml	Updates cache keys and maven-version to 3.9.15.
.github/workflows/copilot-setup-steps.yml	Updates cache keys and maven-version to 3.9.15.
.github/workflows/codeql-analysis.yml	Updates cache keys and maven-version to 3.9.15.
.github/skills/github-actions-workflows/SKILL.md	Updates documented build environment Maven version to 3.9.15.
.github/release-drafter.yml	Updates release template tech stack line to Maven 3.9.15.
.github/copilot-instructions.md	Updates Copilot instruction doc references to Maven 3.9.15.
.github/agents/stack-specialist.md	Updates agent stack description to Maven 3.9.15.
.github/WORKFLOWS.md	Updates workflow environment docs to Maven 3.9.15.
.github/MAVEN_CACHING_STRATEGY.md	Updates documented cache key examples to Maven 3.9.15.
.devcontainer/devcontainer.json	Updates devcontainer Java feature mavenVersion to 3.9.15.
.devcontainer/Dockerfile	Updates Dockerfile MAVEN_VERSION arg to 3.9.15.

[Copilot]

There is still a Maven 3.9.14 reference in custom-instructions/repo/.github/copilot-instructions.md, so the repo isn’t fully aligned on 3.9.15 as described. Please update that copy too, or narrow the PR description/scope to exclude the custom-instructions/ template.