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.

tests/unit/test_infra/test_lancedb/test_lancedb_manager.py

@@ -0,0 +1,72 @@
+"""LanceDB manager singletons.
+
+Verifies ``get_connection`` / ``get_table`` / ``dispose_connection``
+are idempotent and rebuild after dispose.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+from lancedb.pydantic import Vector
+
+from everos.core.persistence import BaseLanceTable
+from everos.infra.persistence.lancedb import lancedb_manager
+
+
+class _DemoVec(BaseLanceTable):
+    """Demo schema — only used by this test module."""
+
+    text: str
+    vector: Vector(3)  # type: ignore[valid-type]
+
+
+@pytest.fixture(autouse=True)
+async def _reset(tmp_path: Path, monkeypatch: pytest.MonkeyPatch):
+    """Point the singleton at an isolated memory-root and reset module state."""
+    monkeypatch.setenv("EVEROS_MEMORY__ROOT", str(tmp_path))
+    lancedb_manager._conn = None
+    lancedb_manager._tables.clear()
+    yield
+    await lancedb_manager.dispose_connection()
+
+
+async def test_get_connection_is_singleton() -> None:
+    c1 = await lancedb_manager.get_connection()
+    c2 = await lancedb_manager.get_connection()
+    assert c1 is c2
+
+
+async def test_get_table_creates_then_caches() -> None:
+    t1 = await lancedb_manager.get_table("demo", _DemoVec)
+    t2 = await lancedb_manager.get_table("demo", _DemoVec)
+    assert t1 is t2
+    assert "demo" in lancedb_manager._tables
+
+
+async def test_get_table_reopens_existing() -> None:
+    """A second connection cycle must reopen (not recreate) the table."""
+    await lancedb_manager.get_table("demo", _DemoVec)
+    await lancedb_manager.dispose_connection()
+
+    t = await lancedb_manager.get_table("demo", _DemoVec)
+    assert t is not None
+    # Round-trip a row to prove the schema survived.
+    await t.add([_DemoVec(text="hello", vector=[0.1, 0.2, 0.3])])
+    assert await t.count_rows() == 1
+
+
+async def test_dispose_resets_state() -> None:
+    await lancedb_manager.get_connection()
+    await lancedb_manager.get_table("demo", _DemoVec)
+    await lancedb_manager.dispose_connection()
+    assert lancedb_manager._conn is None
+    assert lancedb_manager._tables == {}
+
+
+async def test_dispose_is_idempotent() -> None:
+    await lancedb_manager.dispose_connection()  # nothing built yet
+    await lancedb_manager.get_connection()
+    await lancedb_manager.dispose_connection()
+    await lancedb_manager.dispose_connection()  # second call must not raise