(chore) Remove AI-generated artefact files and stray files from repository root

[grantfox-oss]

Body:
Summary
The repository root currently contains dozens of files that appear to have been committed directly from AI-generated PR descriptions, task summaries, and internal working notes. These files make the project look unmaintained and create confusion for new contributors trying to understand the actual codebase structure.
Files to remove
The following files serve no purpose for contributors or users and must be deleted:

TASK_3_COMPLETION_SUMMARY.md, TASK_3_FINAL_REPORT.md
TASK_4_SECURITY_HARDENING_SUMMARY.md
TASK_5_WASM_SANDBOX_SUMMARY.md
TASK_6_CLI_TOOL_SUMMARY.md
PR_DESCRIPTION_174.md, PULL_REQUEST.md
DELIVERABLES.md, MICROSERVICES_DELIVERABLES.md
RECONCILIATION_DELIVERY.md, RECONCILIATION_IMPLEMENTATION.md, RECONCILIATION_QUICKSTART.md
RESILIENCE_DELIVERABLES.md, RESILIENCE_IMPLEMENTATION_GUIDE.md, RESILIENCE_QUICK_REFERENCE.md
IMPLEMENTATION_SUMMARY.md, IMPLEMENTATION_SUMMARY.txt, IMPLEMENTATION_ARCHITECTURE_DOCS.md
REAL_TIME_STREAMING_SUMMARY.md
MICROSERVICES_EXECUTIVE_SUMMARY.md, MICROSERVICES_INDEX.md, MICROSERVICES_VISUAL_GUIDE.md
SCHEMA_ENHANCEMENTS.md, CODEBASE_ANALYSIS.md
TEST_LINTER.md
GABC...WXYZ (invalid filename committed to root)
0 (empty or stray file committed to root)

Acceptance criteria

All files listed above are deleted from the repository
Any content that is genuinely useful (e.g. architecture diagrams, security guidance) is consolidated into the appropriate existing doc: ARCHITECTURE.md, SECURITY_HARDENING_GUIDE.md, or docs/
PULL_REQUEST_TEMPLATE.md is moved to .github/PULL_REQUEST_TEMPLATE.md so GitHub uses it automatically
git ls-files | head -60 no longer shows these files
No other source files, tests, or configs are affected

[happyboy24]

CAN I WORK ON THIS PLEASE

[gloskull]

Hi, I’d love to work on this issue. I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I understand the task clearly and can deliver a clean, efficient, well-tested solution on time, with strong focus on code quality and maintainability. My PR will be submitted in under 10 hours.

[ODbeke]

I'd like to take on the repository cleanup task.

Keeping a clean repository root is vital for developer experience and project credibility. Having managed several codebase cleanups and documentation migrations in the past, I'm a great fit for this because I will:

Audit before deleting: Carefully extract any useful architecture details or security guidance and merge them into ARCHITECTURE.md or SECURITY_HARDENING_GUIDE.md before deleting the source files.
Standardize configuration: Correctly place the PR template in the .github/ directory for automated platform support.
Execute safely: Ensure no source, test, or config files are touched, and verify the cleanup.
With my background in repository maintenance and Git workflow optimization, I can deliver this cleanly and quickly.

[Opeyemi01-del]

Hi, I'd like to take this one on!

I'll audit the repository root, identify AI-generated artefacts and stray files, and open a clean PR removing them. I'll double-check that nothing being deleted is actually referenced elsewhere in the codebase before removing.

Please assign it to me if it's still available!

[clintjeff2]

Hello, I have 6 years of experience working on tasks like this and handling similar challenges across backend, frontend, and smart-contract development. I have carefully read and fully understood the task requirements, and I am confident I can deliver a clean, efficient, and well-tested solution promptly. I always ensure high-quality implementation, maintainability, and adherence to best practices.

Pull request in 5 hours.

[Samueltorres22]

I'm a full-stack developer comfortable with repository maintenance and open source contribution workflows. This is a well-defined cleanup task — I'll delete all listed artefact files, move PULL_REQUEST_TEMPLATE.md to .github/, consolidate any genuinely useful content into the appropriate existing docs, and verify with git ls-files that the root is clean. No source files or configs will be affected. I can submit a PR within 24 hours