[Sync] Update project files from source repository (ead8752)

[mrz1836]

What Changed

• Updated MAGE_X_VERSION from v1.13.0 to v1.15.0 in .github/.env.base
• Updated MAGE_X_GORELEASER_VERSION from v2.13.1 to v2.13.2 in .github/.env.base
• Updated MAGE_X_YAMLFMT_VERSION from v0.20.0 to v0.21.0 in .github/.env.base
• Added new MAGE_X_BENCHSTAT_VERSION=v0.0.0-20251208221838-04cf7a2dca90 configuration in .github/.env.base
• Updated Gitpod workspace configuration comments in .gitpod.yml to be more generic (changed from "go-subtree" to "this project" and clarified MAGE-X usage)
• Modified emoji and wording in Gitpod setup task messages (changed "📥 Downloading" to "🔽 Downloading" and updated other setup messages)
• Added new GitHub Actions for benchstat setup (.github/actions/setup-benchstat/action.yml) and statistics upload (.github/actions/upload-statistics/action.yml)
• Updated documentation in .github/tech-conventions/README.md and .github/tech-conventions/mage-x.md with new content structure
• Modified GitHub workflow files for fortress completion statistics, coverage, dependabot auto-merge, and test matrix

Why It Was Necessary

• Keep build tooling and dependencies up to date with the latest versions of MAGE-X and its associated tools
• Add benchstat support to enable performance benchmarking and statistical analysis capabilities
• Improve developer experience with clearer Gitpod workspace configuration and documentation
• Standardize and enhance GitHub Actions workflows with dedicated actions for statistics and benchmarking

Testing Performed

• Verified that MAGE-X v1.15.0 is compatible with existing workflows and build processes
• Validated that new benchstat action integrates correctly with GitHub Actions workflows
• Confirmed Gitpod workspace setup completes successfully with updated configuration
• Ensured all updated tool versions are available and functionally compatible

Impact / Risk

• Low Risk: Version bumps are incremental and represent stable releases of build tools
• No Breaking Changes: Updates maintain backward compatibility with existing automation and workflows
• Improved Capabilities: Addition of benchstat tooling enables new performance analysis features
• Developer Experience: Generic workspace comments improve repository reusability and onboarding clarity

[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

[mrz1836]

LGTM!