chore(governance): add linked-issue and wiki guidance

[srpatcha]

Fixes #32

Summary

• preserve and extend EoSim's existing agent-role guidance with repository-specific architecture, trust boundaries, and validation commands
• add the canonical linked-issue workflow pinned to 92cb596c773496ec4df76717e8acf0e6b7700f73
• require a recognized same-repository closing issue while preserving the existing change, testing, checklist, screenshots, and notes sections and repairing corrupted labels
• snapshot all six published Wiki pages under docs/wiki/ from Wiki revision e61daacef6221f167b862fe3159b200f6b616cfc

Validation

• live duplicate check: all 11 remote branches, 25 pull requests across all states, and six genuine issues across all states; zero governance rollout matches
• YAML parsed successfully; both policy references use the canonical SHA and permissions are read-only
• workflow is byte-identical to the canonical rollout file
• strict Markdown lint on AGENTS.md and .github/PULL_REQUEST_TEMPLATE.md: 0 errors
• publication-compatible Markdown lint on all six docs/wiki pages: 0 errors
• all six relative Wiki link targets resolve and Git blob IDs match the published Wiki
• git diff --cached --check: passed
• python -X utf8 -m pytest tests/unit -q: 1697 passed, 4 failed, 3 skipped; all four failures are the pre-existing Windows environment blocker make not installed
• python -m ruff check eosim: pre-existing repository-wide lint findings remain; this documentation-only change does not modify Python

Risk and rollout

Documentation and pull-request policy only. The reusable workflow has read-only permissions and immutable policy references. Rollback is a revert of this commit. No repository settings or default-branch content were changed directly.