Wire up reporting (plots, BOM, summary, animation) and a working CLI (Stage 7)

- report/plots.py: current/field/velocity plots per stage, Agg backend so
  it works headless in Docker/on a server
- report/bom.py: itemized bill of materials with real component prices
- report/summary.py: honest text/JSON summary including a
  "model limitations" section and a saturation warning flag per stage
- report/animate.py: the visualization the user explicitly asked for --
  a GIF of the slug flying through the tube with each coil glowing by its
  instantaneous current, reconstructing the pre-trigger ballistic flight
  segment (not just the stored discharge phase) for a continuous timeline
- cli.py: sweep/evolve/simulate/report subcommands now actually call the
  underlying modules instead of being stubs
- Extended StageResult/StageOutcome with the coil/entry-state fields the
  report layer needed (mu_eff, turns, coil_length, entry_x/v) rather than
  recomputing them by other means

Verified end-to-end through `docker compose run`, not just pytest: a real
sweep (30 runs, 11 feasible) followed by `report --animate` produced a
correct GIF/plots/BOM/summary for the actual best result found (32.8%
efficiency, 982 RUB) -- not a synthetic fixture.

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

tests/test_cli_smoke.py

@@ -0,0 +1,55 @@
+from pathlib import Path
+
+from gausse.cli import main
+from gausse.storage.database import fetch_runs, open_connection
+
+
+def test_cli_sweep_writes_database(tmp_path):
+    db_path = tmp_path / "runs.sqlite3"
+    rc = main(["sweep", "--db", str(db_path), "--n", "10", "--workers", "2", "--seed", "1", "--max-stages", "2"])
+    assert rc == 0
+    assert db_path.exists()
+    conn = open_connection(db_path)
+    assert len(fetch_runs(conn)) == 10
+    conn.close()
+
+
+def test_cli_sweep_then_report_end_to_end(tmp_path):
+    db_path = tmp_path / "runs.sqlite3"
+    out_dir = tmp_path / "report"
+    rc = main(["sweep", "--db", str(db_path), "--n", "40", "--workers", "2", "--seed", "2"])
+    assert rc == 0
+
+    rc2 = main(["report", "--db", str(db_path), "--out", str(out_dir), "--top", "1"])
+    assert rc2 == 0
+    rank_dirs = list(out_dir.glob("rank1_*"))
+    assert len(rank_dirs) == 1
+    run_dir = rank_dirs[0]
+    assert (run_dir / "summary.txt").exists()
+    assert (run_dir / "summary.json").exists()
+    assert (run_dir / "bom.txt").exists()
+    assert (run_dir / "current.png").exists()
+    assert (run_dir / "velocity_vs_position.png").exists()
+
+
+def test_cli_simulate_single_run_id(tmp_path):
+    db_path = tmp_path / "runs.sqlite3"
+    out_dir = tmp_path / "sim_out"
+    main(["sweep", "--db", str(db_path), "--n", "5", "--workers", "1", "--seed", "3", "--max-stages", "2"])
+
+    conn = open_connection(db_path)
+    row = fetch_runs(conn)[0]
+    conn.close()
+
+    rc = main(["simulate", "--db", str(db_path), "--run-id", row.run_id, "--out", str(out_dir)])
+    assert rc == 0
+    assert (out_dir / "summary.txt").exists()
+
+
+def test_cli_report_with_empty_database_reports_error_not_crash(tmp_path):
+    db_path = tmp_path / "empty.sqlite3"
+    from gausse.storage.database import open_connection as oc
+
+    oc(db_path).close()  # создаёт пустую (но валидную) базу
+    rc = main(["report", "--db", str(db_path), "--out", str(tmp_path / "out")])
+    assert rc == 1