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.

CHANGELOG.md

@@ -0,0 +1,40 @@
+# Changelog
+
+All notable changes to **EverOS** are documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+_Unreleased changes on `dev` will be listed here._
+
+## [1.0.0] - 2026-06-03
+
+First public release of EverOS — a Markdown-first memory extraction framework
+for AI agents.
+
+### Added
+
+- **Markdown as source of truth** — all memory persists as plain `.md` files you
+  can open, edit, grep, and version with Git.
+- **Lightweight three-piece storage** — Markdown (truth) + SQLite (state / queue
+  / audit) + LanceDB (vector + BM25 + scalar index). No external services
+  required.
+- **Hybrid retrieval** — BM25, vector, and scalar filtering in a single LanceDB
+  query.
+- **Cascade index sync** — editing a `.md` file triggers a file watcher →
+  entry-level diff → sub-second LanceDB sync.
+- **Dual-track memory** — user-track (Episodes / Profiles) and agent-track
+  (Cases / Skills).
+- **Multi-source extraction** — conversations, workflows, agent traces, and file
+  knowledge.
+- **CLI + HTTP API** — the `everos` command-line tool and a FastAPI server,
+  async-first throughout.
+- **Pluggable providers** — LLM / embedding / rerank via the OpenAI-compatible
+  protocol (works with OpenAI, OpenRouter, vLLM, Ollama, …).
+- **Decoupled algorithms** — memory extraction algorithms live in the standalone
+  `everalgo-*` libraries published on PyPI.
+
+[Unreleased]: https://github.com/EverMind-AI/EverOS/compare/v1.0.0...HEAD
+[1.0.0]: https://github.com/EverMind-AI/EverOS/releases/tag/v1.0.0