feat(cli): tht session list --json + session show --json (Task 7)

- Add _list_sessions(sessions_root) pure helper: scans sessions dir,
  returns list[dict] with id/status/question/summary/created_at/
  updated_at/author, sorted by created_at desc.
- Add `tht session list` command: --json emits pristine JSON array,
  human mode prints one line per session.
- Add --json flag to `tht session show`: emits manifest
  (model_dump by_alias) + phase (current_phase) + has_schema_linking.
- Tests: 8 tests in test_session_list_json.py (TDD red→green).
- Full suite: 230 passed (--ignore=tests/l2).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

harness/tests/test_session_list_json.py

@@ -0,0 +1,162 @@
+"""Tests for `tht session list --json` and `tht session show --json` (Task 7)."""
+import json
+
+import pytest
+from typer.testing import CliRunner
+
+from tht.cli.session_cmd import _list_sessions, session_app
+from tht.session.store import create_session
+
+
+def _make_db():
+    from tht.config import DatabaseConfig
+
+    return DatabaseConfig(
+        database="testdb",
+        user="testuser",
+        password="testpass",  # noqa: S106
+        **{"schema": "public"},
+    )
+
+
+# ---------------------------------------------------------------------------
+# Unit: _list_sessions helper
+# ---------------------------------------------------------------------------
+
+
+def test_list_sessions_returns_all_created(tmp_path):
+    db = _make_db()
+    m1 = create_session("prima domanda", db, tmp_path)
+    m2 = create_session("seconda domanda", db, tmp_path)
+    rows = _list_sessions(tmp_path)
+    ids = [r["id"] for r in rows]
+    assert m1.id in ids
+    assert m2.id in ids
+
+
+def test_list_sessions_required_keys(tmp_path):
+    db = _make_db()
+    create_session("qualsiasi domanda", db, tmp_path)
+    rows = _list_sessions(tmp_path)
+    assert len(rows) >= 1
+    required = {"id", "status", "question", "created_at"}
+    assert required.issubset(rows[0].keys())
+
+
+def test_list_sessions_sorted_desc(tmp_path):
+    db = _make_db()
+    create_session("prima", db, tmp_path)
+    create_session("seconda", db, tmp_path)
+    rows = _list_sessions(tmp_path)
+    dates = [r["created_at"] for r in rows]
+    assert dates == sorted(dates, reverse=True)
+
+
+def test_list_sessions_empty_dir(tmp_path):
+    rows = _list_sessions(tmp_path)
+    assert rows == []
+
+
+# ---------------------------------------------------------------------------
+# CLI: tht session list --json
+# ---------------------------------------------------------------------------
+
+
+def test_cli_list_json_valid(tmp_path, monkeypatch):
+    db = _make_db()
+    m = create_session("test question", db, tmp_path)
+
+    # Patch _load_config_or_exit so we don't need a real config file
+    from tht.cli import session_cmd
+
+    class FakePaths:
+        sessions = tmp_path
+
+    class FakeCfg:
+        paths = FakePaths()
+
+    monkeypatch.setattr(session_cmd, "_load_config_or_exit", lambda _: FakeCfg())
+
+    runner = CliRunner()
+    result = runner.invoke(session_app, ["list", "--json"])
+    assert result.exit_code == 0, result.output
+    rows = json.loads(result.output)
+    assert isinstance(rows, list)
+    ids = [r["id"] for r in rows]
+    assert m.id in ids
+
+
+def test_cli_list_human_no_json_noise(tmp_path, monkeypatch):
+    """Human mode must not emit JSON."""
+    db = _make_db()
+    create_session("human question", db, tmp_path)
+
+    from tht.cli import session_cmd
+
+    class FakePaths:
+        sessions = tmp_path
+
+    class FakeCfg:
+        paths = FakePaths()
+
+    monkeypatch.setattr(session_cmd, "_load_config_or_exit", lambda _: FakeCfg())
+
+    runner = CliRunner()
+    result = runner.invoke(session_app, ["list"])
+    assert result.exit_code == 0
+    # Must not be parseable as JSON array
+    with pytest.raises(json.JSONDecodeError):
+        json.loads(result.output)
+
+
+# ---------------------------------------------------------------------------
+# CLI: tht session show --json
+# ---------------------------------------------------------------------------
+
+
+def test_cli_show_json_valid(tmp_path, monkeypatch):
+    db = _make_db()
+    m = create_session("domanda show json", db, tmp_path)
+
+    from tht.cli import session_cmd
+
+    class FakePaths:
+        sessions = tmp_path
+
+    class FakeCfg:
+        paths = FakePaths()
+        database = db
+
+    monkeypatch.setattr(session_cmd, "_load_config_or_exit", lambda _: FakeCfg())
+
+    runner = CliRunner()
+    result = runner.invoke(session_app, ["show", m.id, "--json"])
+    assert result.exit_code == 0, result.output
+    data = json.loads(result.output)
+    assert data["id"] == m.id
+    assert "phase" in data
+    assert "has_schema_linking" in data
+
+
+def test_cli_show_json_stdout_pristine(tmp_path, monkeypatch):
+    """--json must produce only valid JSON on stdout (no ANSI color codes or extra lines)."""
+    db = _make_db()
+    m = create_session("pristine stdout test", db, tmp_path)
+
+    from tht.cli import session_cmd
+
+    class FakePaths:
+        sessions = tmp_path
+
+    class FakeCfg:
+        paths = FakePaths()
+        database = db
+
+    monkeypatch.setattr(session_cmd, "_load_config_or_exit", lambda _: FakeCfg())
+
+    runner = CliRunner()
+    result = runner.invoke(session_app, ["show", m.id, "--json"])
+    assert result.exit_code == 0, result.output
+    # stdout must parse cleanly as JSON
+    data = json.loads(result.output)
+    assert isinstance(data, dict)

harness/tht/cli/session_cmd.py

@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 
 import typer
@@ -22,6 +23,47 @@ def load_session_or_exit(cfg, session_id: str):
         raise typer.Exit(code=1)
 
 
+def _list_sessions(sessions_root: Path) -> list[dict]:
+    """Return session summary dicts sorted by created_at desc (pure helper, no I/O side-effects)."""
+    from tht.session.models import SessionManifest
+
+    MANIFEST_NAME = "session_manifest.yaml"
+    out = []
+    if not sessions_root.exists():
+        return out
+    for d in sessions_root.iterdir():
+        manifest_path = d / MANIFEST_NAME
+        if not manifest_path.exists():
+            continue
+        m = SessionManifest.from_yaml(manifest_path)
+        out.append({
+            "id": m.id,
+            "status": m.status,
+            "question": m.question,
+            "summary": m.summary,
+            "created_at": m.created_at.isoformat(),
+            "updated_at": m.updated_at.isoformat() if m.updated_at else None,
+            "author": m.author,
+        })
+    out.sort(key=lambda r: r["created_at"], reverse=True)
+    return out
+
+
+@session_app.command("list")
+def list_cmd(
+    json_out: bool = typer.Option(False, "--json", help="Emetti JSON su stdout (pristine)."),
+    config: Path = CONFIG_OPT,
+) -> None:
+    """Elenca le sessioni esistenti."""
+    cfg = _load_config_or_exit(config)
+    rows = _list_sessions(cfg.paths.sessions)
+    if json_out:
+        typer.echo(json.dumps(rows, ensure_ascii=False, indent=2))
+        return
+    for r in rows:
+        typer.echo(f"{r['id']}  [{r['status']}]  {r['summary'] or r['question'][:60]}")
+
+
 @session_app.command("new")
 def new_cmd(
     question: str = typer.Argument(..., help="La domanda in linguaggio naturale."),
@@ -56,13 +98,29 @@ def set_question_cmd(
 
 
 @session_app.command("show")
-def show_cmd(session_id: str = typer.Argument(...), config: Path = CONFIG_OPT) -> None:
+def show_cmd(
+    session_id: str = typer.Argument(...),
+    json_out: bool = typer.Option(False, "--json", help="Emetti JSON su stdout (pristine)."),
+    config: Path = CONFIG_OPT,
+) -> None:
     """Stato della sessione: manifest + decisioni registrate (per la ripresa)."""
     from tht.decisions import list_decisions
+    from tht.phase import current_phase
 
     cfg = _load_config_or_exit(config)
     manifest = load_session_or_exit(cfg, session_id)
-    decisions = list_decisions(session_dir(cfg, session_id))
+    sdir = session_dir(cfg, session_id)
+
+    if json_out:
+        has_schema_linking = (sdir / "schema_linking.json").exists()
+        phase = current_phase(sdir)
+        data = manifest.model_dump(mode="json", by_alias=True)
+        data["phase"] = phase
+        data["has_schema_linking"] = has_schema_linking
+        typer.echo(json.dumps(data, ensure_ascii=False, indent=2))
+        return
+
+    decisions = list_decisions(sdir)
     typer.echo(f"id       : {manifest.id}")
     typer.echo(f"stato    : {manifest.status}")
     typer.echo(f"domanda  : {manifest.question}")
@@ -70,7 +128,7 @@ def show_cmd(session_id: str = typer.Argument(...), config: Path = CONFIG_OPT) -
     typer.echo(f"decisioni: {len(decisions)}")
     for d in decisions[-10:]:
         typer.echo(f"  [{d.seq}] {d.type}: {d.subject}" + (f" — {d.detail}" if d.detail else ""))
-    linking = session_dir(cfg, session_id) / "schema_linking.json"
+    linking = sdir / "schema_linking.json"
     typer.echo(f"schema_linking.json: {'presente' if linking.exists() else 'assente'}")