Implement versiond M1: inotify monitor, versioning, diff, restore, systemd install

FastAPI service on 127.0.0.1:9922 that monitors user-chosen directories
with pruned inotify watches, stores versions in a local content-addressed
spool indexed in SQLite, coalesces bursts (first + last), and offers
history, diff and dry-run-first bulk restore. Includes a CLI with a
systemd user unit installer.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_units.py

@@ -0,0 +1,100 @@
+import asyncio
+from pathlib import PurePath
+
+from versiond.db import Database
+from versiond.diff import hunks, unified
+from versiond.filters import Filters
+from versiond.ingest import Coalescer, Repository
+from versiond.store import BlobStore
+
+
+def test_filters_paths():
+    f = Filters()
+    ok = ["app.py", "src/main.go", ".env", ".env.production", "Makefile", "pkg/package.json", ".gitignore"]
+    for p in ok:
+        assert f.path_reason(PurePath(p)) is None, p
+    rejected = {
+        "node_modules/x/index.js": "ignored-directory",
+        ".git/config": "ignored-directory",
+        "src/__pycache__/a.cpython-312.pyc": "ignored-directory",
+        "a.pyc": "ignored-extension",
+        ".bashrc_local": "hidden-file",
+        "notes.txt~": "temporary-file",
+        "main.py.swp": "ignored-extension",
+        "venv/lib/x.py": "ignored-directory",
+        "target/debug/build.rs": "ignored-directory",
+        "4913": "temporary-file",
+        "src/pkg.egg-info/PKG-INFO": "ignored-directory",
+    }
+    for p, reason in rejected.items():
+        assert f.path_reason(PurePath(p)) == reason, p
+    assert f.size_reason(204_800) is None
+    assert f.size_reason(204_801) == "file-too-large"
+    assert f.content_reason(b"abc\x00def") == "binary-content"
+
+
+def test_filter_patterns():
+    f = Filters(patterns=("*.log", "secret/*"))
+    assert f.path_reason(PurePath("x/debug.log")) == "ignored-pattern"
+    assert f.path_reason(PurePath("secret/key.txt")) == "ignored-pattern"
+    assert f.path_reason(PurePath("src/key.txt")) is None
+
+
+def test_diff_unified():
+    a = b"one\ntwo\nthree\n"
+    b = b"one\n2\nthree\nfour\n"
+    out = unified(hunks(a, b), "a", "b")
+    assert "-two\n+2\n" in out and "+four\n" in out
+    assert hunks(b"x  y\n", b"x y\n", ignore_whitespace=True) == []
+
+
+def _repo(tmp_path):
+    db = Database(tmp_path / "index.sqlite")
+    return Repository(db, BlobStore(tmp_path / "spool"), Filters())
+
+
+def test_coalescer_keeps_first_and_last(tmp_path):
+    repo = _repo(tmp_path)
+    path = str(tmp_path / "f.py")
+
+    async def run():
+        c = Coalescer(repo, window=0.2, max_hold=1.0, per_hour=100)
+        statuses = [c.submit(path, f"v{i}\n".encode(), "test", "edit")["status"] for i in range(6)]
+        await asyncio.sleep(0.5)
+        return statuses
+
+    statuses = asyncio.run(run())
+    assert statuses[0] == "committed"
+    assert set(statuses[1:]) == {"coalesced"}
+    file = repo.db.file_by_path(path)
+    contents = [repo.blobs.get(v["blob_sha256"]) for v in reversed(repo.db.history(file["id"]))]
+    assert contents == [b"v0\n", b"v5\n"]
+
+
+def test_coalescer_rate_limit_keeps_newest(tmp_path):
+    repo = _repo(tmp_path)
+    path = str(tmp_path / "f.py")
+
+    async def run():
+        c = Coalescer(repo, window=0.05, max_hold=0.1, per_hour=2)
+        c.submit(path, b"a", "t", "e")
+        await asyncio.sleep(0.1)
+        c.submit(path, b"b", "t", "e")
+        await asyncio.sleep(0.2)
+        status = c.submit(path, b"c", "t", "e")["status"]
+        await asyncio.sleep(0.2)
+        flushed = c.flush()
+        return status, flushed
+
+    status, flushed = asyncio.run(run())
+    assert status == "coalesced"
+    assert flushed == 1  # over the limit it waits, and shutdown still stores it
+    file = repo.db.file_by_path(path)
+    assert repo.blobs.get(repo.db.latest_version(file["id"])["blob_sha256"]) == b"c"
+
+
+def test_dedupe_unchanged(tmp_path):
+    repo = _repo(tmp_path)
+    path = str(tmp_path / "f.py")
+    assert repo.commit(path, b"x", "t", "e")["status"] == "committed"
+    assert repo.commit(path, b"x", "t", "e")["status"] == "unchanged"