chore: initialize EverOS 1.0.0

md-first memory extraction framework for AI agents.

Markdown is the single source of truth; SQLite holds state and LanceDB
provides the rebuildable vector + BM25 + scalar index. The codebase follows
a single-direction DDD layering (entrypoints -> service -> memory -> infra,
with component / core / config cross-cutting) enforced by import-linter.

Engineering surface:
- Coding conventions in .claude/rules/ (path-scoped) and workflows in
  .claude/skills/ (/commit, /new-branch, /pr).
- GitHub Actions CI runs make lint + test + integration; pre-commit mirrors
  the gates locally (ruff, hygiene hooks, gitlint commit-msg).
- Commit messages follow Conventional Commits, enforced by gitlint.
- make lint also enforces datetime two-zone discipline and OpenAPI drift.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,37 @@
+## Summary
+
+<!-- What changed, and why? -->
+
+## Area
+
+<!-- Mark the relevant option with an x. -->
+
+- [ ] Architecture method
+- [ ] Benchmark
+- [ ] Use case
+- [ ] Documentation
+- [ ] Developer experience
+- [ ] CI, build, or release
+
+## Verification
+
+<!-- List commands run, manual checks, screenshots, or reasons verification was not needed. -->
+
+```text
+
+```
+
+## Checklist
+
+- [ ] I kept the change scoped to the relevant area.
+- [ ] I updated docs, examples, or setup notes when behavior changed.
+- [ ] I added or updated tests when the change affects behavior.
+- [ ] I did not commit secrets, `.env` files, dependency folders, or generated output.
+- [ ] Active relative links in Markdown files resolve.
+
+## Notes for Reviewers
+
+<!-- Anything reviewers should pay special attention to? -->
+
+By submitting this pull request, I agree that my contribution is licensed under
+the Apache License 2.0.