Harness foundation: INTENT, ADR-001, architecture, prototype adoption

- INTENT.md: three-layer model (blueprint/instance/harness), single
  shared runtime, never-become boundaries
- ADR-001 (accepted): DEC-2026-002 resolution — one harness repo for
  all projects; instances are declarative state in consuming repos
- docs/architecture.md: components, contracts (manifest, tool
  profiles, completion events, credential lanes), deployment shape
- agent_harness/: executor-worker prototype adopted and renamed
  (6/6 tests green); HARNESS-WP-0001 initial workplan (7 tasks)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_mailscan.py

@@ -0,0 +1,117 @@
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+import pytest
+
+from agent_harness import mailscan
+
+
+class FakeCompleted:
+    def __init__(self, returncode=0, stdout="", stderr=""):
+        self.returncode = returncode
+        self.stdout = stdout
+        self.stderr = stderr
+
+
+def _repo_with_reports(tmp_path: Path, names: list[str]) -> Path:
+    repo = tmp_path / "binky-control"
+    (repo / "mailmeta" / "reports").mkdir(parents=True)
+    for name in names:
+        (repo / "mailmeta" / "reports" / name).write_text("header\nrow1\nrow2\n")
+    return repo
+
+
+def test_mail_scan_approle_lane_and_new_report(tmp_path, monkeypatch) -> None:
+    repo = _repo_with_reports(tmp_path, ["old.csv"])
+    approle = tmp_path / "approle"
+    approle.mkdir()
+    (approle / "role_id").write_text("rid\n")
+    (approle / "secret_id").write_text("sid\n")
+    monkeypatch.setenv("EXECUTOR_APPROLE_DIR", str(approle))
+
+    calls: list[list[str]] = []
+
+    def fake_run(cmd, **kwargs):
+        calls.append(cmd)
+        if cmd[0] == "bao" and cmd[1] == "write":
+            assert "auth/approle/login" in cmd
+            return FakeCompleted(stdout="tok123\n")
+        if cmd[0] == "bao" and cmd[1] == "kv":
+            assert kwargs["env"]["BAO_TOKEN"] == "tok123"
+            return FakeCompleted(stdout="value\n")
+        if cmd[1] == "-m":  # python3 -m email_connect.cli ...
+            env = kwargs["env"]
+            assert env["IMAP_USERNAME"] == "value"
+            assert env["IMAP_PASSWORD"] == "value"
+            (repo / "mailmeta" / "reports" / "new-report.csv").write_text(
+                "header\na\nb\nc\n"
+            )
+            return FakeCompleted()
+        raise AssertionError(f"unexpected command: {cmd}")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    events: list[dict] = []
+    monkeypatch.setattr(
+        mailscan.hub,
+        "post_progress_event",
+        lambda **kw: events.append(kw) or True,
+    )
+
+    result = mailscan.run_mail_scan(repo)
+
+    assert result.ok is True
+    assert result.auth_lane == "approle"
+    assert result.report_path == "new-report.csv"
+    assert result.new_messages == 3
+    assert events[0]["event_type"] == "binky_mail_intake"
+    # secret values must never appear in the hub event
+    assert "value" not in str(events[0]["detail"])
+
+
+def test_mail_scan_failure_does_not_emit_intake_event(tmp_path, monkeypatch) -> None:
+    repo = _repo_with_reports(tmp_path, [])
+    monkeypatch.delenv("EXECUTOR_APPROLE_DIR", raising=False)
+
+    def fake_run(cmd, **kwargs):
+        if cmd[0] == "bao":
+            return FakeCompleted(stdout="value\n")
+        return FakeCompleted(returncode=3, stderr="imap connect refused")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    events: list[dict] = []
+    monkeypatch.setattr(
+        mailscan.hub,
+        "post_progress_event",
+        lambda **kw: events.append(kw) or True,
+    )
+
+    result = mailscan.run_mail_scan(repo)
+
+    assert result.ok is False
+    assert result.auth_lane == "ambient"
+    assert "exited 3" in result.reason
+    assert events[0]["event_type"] == "executor_run"
+
+
+def test_mail_scan_reports_failure_when_bao_unavailable(tmp_path, monkeypatch) -> None:
+    repo = _repo_with_reports(tmp_path, [])
+    monkeypatch.delenv("EXECUTOR_APPROLE_DIR", raising=False)
+
+    def fake_run(cmd, **kwargs):
+        return FakeCompleted(returncode=2, stderr="permission denied")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    events: list[dict] = []
+    monkeypatch.setattr(
+        mailscan.hub,
+        "post_progress_event",
+        lambda **kw: events.append(kw) or True,
+    )
+
+    result = mailscan.run_mail_scan(repo)
+
+    assert result.ok is False
+    assert "bao kv failed" in result.reason
+    assert events[0]["event_type"] == "executor_run"