docs(governance): add repository contribution controls

[srpatcha]

Fixes #43

Summary

• replace the generic agent scaffold with guidance for eApps' native, web, mobile, desktop, extension, tool, enterprise, catalog, and storefront surfaces
• add the canonical linked-issue workflow pinned to 92cb596c773496ec4df76717e8acf0e6b7700f73
• reconcile the repository PR template, preserving its platform test checklist while requiring a recognized same-repository closing issue and consolidating duplicate case-only paths
• snapshot all six published Wiki pages under docs/wiki/ from Wiki revision 4096c20fd30524c9302574df9df4533a26aae0f2

Validation

• YAML parsed successfully and the workflow matches the canonical template after exact SHA substitution
• npx --yes markdownlint-cli2 AGENTS.md .github/PULL_REQUEST_TEMPLATE.md: 0 errors
• all six relative Wiki link targets resolve
• all six source-controlled Wiki pages match the published Wiki byte-for-byte
• python -m unittest discover across functional, performance, and simulation suites: 7 passed
• git diff --check: passed

Risk and rollout

Documentation and pull-request policy only. The reusable workflow has read-only permissions. The initial run_all_tests.py invocation could not find the Unix-only python3 command on Windows; the three underlying suites were rerun successfully with the available Python interpreter.