feat(understand): the snapshot, the vocabulary and the label parsers; MAX_DXF_BYTES 512 MB; the office extra

Track H's foundation, landed on main before its three groups branch.

- engineering/understand/snapshot.py: one bulk read of a drawing into frozen
  WCS records (OCS translated through backends/ocs.py, text decoded, an
  INSERT boxed by its block geometry without its attribute texts). A DXF is
  read with ezdxf after the size check; the headless engine's document is
  read under its own lock; the live engine exports the active document with
  Document.Export(<tmp>/snap, "DXF", <set of all>) - never renamed, deleted
  afterwards - and a DWG is opened read-only, exported and closed. Measured on
  AutoCAD 2026: ".dxf" is refused with Invalid argument, the file lands as
  snap.DXF, model space, paper space and unused block definitions all reach
  it, and the selection set does not narrow a DXF export.
- engineering/understand/labels.py: %%c, \U+2205, the U+2300 sign, o-stroke
  and MTEXT format runs all read as one diameter spelling; sizes are kept as
  drawn and never equated; Cyrillic look-alike capitals fold into Latin tags;
  panels, wiring callouts and electrical data (kW, phases, volts, N, VFD) in
  EN / TR / RU / NL / DE. A power that is not written stays None.
- engineering/understand/vocab.py: layer classification with a confidence and
  the deciding keyword, supply / return words, room labels and block kinds in
  five languages. A CIP layer without a direction word is not guessed.
- MAX_DXF_BYTES defaults to 512 MB (a real layout was 188 MB); the refusal
  names the size and the variable. New `office` extra (openpyxl), also in
  `full`; uv.lock regenerated.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd

tests/test_understand_vocab.py

@@ -0,0 +1,234 @@
+"""The multilingual vocabulary: layer names, direction words, room labels, block kinds.
+
+Every layer name below is one a drafter would write; the ones in the synthetic
+plant pair (tests/fixtures/plant_pair.py) are here too, because that is what the
+readers above this module are measured on.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from engineering.understand.vocab import (
+    DISCIPLINES,
+    EQUIPMENT_KINDS,
+    LANGUAGES,
+    SERVICES,
+    classify_layer,
+    equipment_kind,
+    fold,
+    room_label,
+    supply_return,
+)
+
+
+def test_the_closed_lists():
+    assert LANGUAGES == ("en", "tr", "ru", "nl", "de")
+    assert SERVICES == (
+        "product",
+        "cip_supply",
+        "cip_return",
+        "glycol_supply",
+        "glycol_return",
+        "steam",
+        "condensate",
+        "cold_water",
+        "hot_water",
+        "ice_water",
+        "compressed_air",
+        "drain",
+        "electrical",
+        "unknown",
+    )
+    assert DISCIPLINES == (
+        "piping",
+        "electrical",
+        "architecture",
+        "equipment",
+        "annotation",
+        "structure",
+        "unknown",
+    )
+    assert EQUIPMENT_KINDS == ("tank", "pump", "valve", "reducer", "motor", "agitator", "panel")
+
+
+def test_fold_strips_diacritics_and_the_turkish_dotless_i():
+    assert fold("DÖNÜŞ") == "donus"
+    assert fold("GİDİŞ") == "gidis"
+    assert fold("çıkış") == "cikis"
+    assert fold("RückLauf") == "rucklauf"
+    assert fold("ПОДАЧА") == "подача"
+    assert fold(None) == ""
+
+
+@pytest.mark.parametrize(
+    ("name", "service", "keyword", "language"),
+    [
+        ("P_product piping", "product", "product", "en"),
+        ("P_cipsupplyline", "cip_supply", "cip", "en"),
+        ("P_cipreturnline", "cip_return", "cip", "en"),
+        ("P_ijswater", "ice_water", "ijswater", "nl"),
+        ("CIP ВОЗВРАТ", "cip_return", "cip", "en"),
+        ("glikol dönüş", "glycol_return", "glikol", "tr"),
+        ("GLYKOL-VORLAUF", "glycol_supply", "glykol", "de"),
+        ("buhar hattı", "steam", "buhar", "tr"),
+        ("КОНДЕНСАТ", "condensate", "конденсат", "ru"),
+        ("P_ICE WATER", "ice_water", "ice water", "en"),
+        ("sıcak su", "hot_water", "sicak su", "tr"),
+        ("DRUCKLUFT", "compressed_air", "druckluft", "de"),
+        ("air_line", "compressed_air", "air", "en"),
+        ("RIOOL", "drain", "riool", "nl"),
+    ],
+)
+def test_service_layers(name, service, keyword, language):
+    row = classify_layer(name)
+    assert row["service"] == service
+    assert row["discipline"] == "piping"
+    assert row["confidence"] == 0.9
+    assert row["keyword"] == keyword
+    assert row["language"] == language
+
+
+def test_electrical_layers_are_their_own_service():
+    for name in ("E_power", "ELEKTRIK", "ЭЛЕКТРИКА", "kabel"):
+        row = classify_layer(name)
+        assert (row["discipline"], row["service"], row["confidence"]) == (
+            "electrical",
+            "electrical",
+            0.9,
+        ), name
+
+
+def test_a_cip_layer_without_a_direction_is_not_guessed():
+    row = classify_layer("P_CIP")
+    assert row == {
+        "discipline": "piping",
+        "service": "unknown",
+        "confidence": 0.6,
+        "keyword": "cip",
+        "language": "en",
+    }
+
+
+def test_a_cip_layer_naming_both_directions_is_not_guessed_either():
+    assert classify_layer("CIP supply return")["service"] == "unknown"
+
+
+def test_a_water_layer_with_no_temperature_is_piping_of_unknown_service():
+    row = classify_layer("P_WATER")
+    assert (row["discipline"], row["service"], row["confidence"]) == ("piping", "unknown", 0.6)
+
+
+@pytest.mark.parametrize(
+    ("name", "discipline", "language"),
+    [
+        ("KLEPPEN", "piping", "nl"),
+        ("VANALAR", "piping", "tr"),
+        ("WALLS", "architecture", "en"),
+        ("MUREN", "architecture", "nl"),
+        ("СТЕНЫ", "architecture", "ru"),
+        ("EQUIPMENT", "equipment", "en"),
+        ("POMPALAR", "equipment", "tr"),
+        ("DIM", "annotation", "en"),
+        ("ÖLÇÜ", "annotation", "tr"),
+        ("KOLONLAR", "structure", "tr"),
+    ],
+)
+def test_discipline_layers(name, discipline, language):
+    row = classify_layer(name)
+    assert (row["discipline"], row["service"], row["confidence"], row["language"]) == (
+        discipline,
+        "unknown",
+        0.9,
+        language,
+    )
+
+
+def test_a_short_keyword_must_start_a_word():
+    assert classify_layer("STAIRS")["service"] != "compressed_air"
+    assert classify_layer("CHAIRS")["discipline"] == "unknown"
+
+
+def test_a_layer_with_no_keyword():
+    assert classify_layer("0") == {
+        "discipline": "unknown",
+        "service": "unknown",
+        "confidence": 0.0,
+        "keyword": None,
+        "language": None,
+    }
+    assert classify_layer("Defpoints")["discipline"] == "unknown"
+
+
+@pytest.mark.parametrize(
+    ("text", "direction"),
+    [
+        ("ПОДАЧА", "supply"),
+        ("ВОЗВРАТ", "return"),
+        ("обратка CIP", "return"),  # обратка
+        ("BESLEME", "supply"),
+        ("DÖNÜŞ", "return"),
+        ("donus hatti", "return"),
+        ("CIP SUPPLY", "supply"),
+        ("return line", "return"),
+        ("AANVOER", "supply"),
+        ("RETOUR", "return"),
+        ("Vorlauf", "supply"),
+        ("RÜCKLAUF", "return"),
+    ],
+)
+def test_supply_and_return_words_in_five_languages(text, direction):
+    assert supply_return(text) == direction
+
+
+def test_a_text_naming_both_or_neither_direction_is_none():
+    assert supply_return("CIP SUPPLY / RETURN") is None
+    assert supply_return("Ø51") is None
+    assert supply_return(None) is None
+
+
+@pytest.mark.parametrize(
+    ("text", "expected"),
+    [
+        ("ROOM 1 PROCESS HALL", {"number": "1", "name": "PROCESS HALL", "language": "en"}),
+        ("ODA 2", {"number": "2", "name": None, "language": "tr"}),
+        ("MAHAL 1.05 SOĞUK ODA", {"number": "1.05", "name": "SOĞUK ODA", "language": "tr"}),
+        (
+            "ПОМЕЩЕНИЕ 2 МОЙКА",
+            {"number": "2", "name": "МОЙКА", "language": "ru"},
+        ),
+        ("RUIMTE 3 opslag", {"number": "3", "name": "opslag", "language": "nl"}),
+        ("Raum 4", {"number": "4", "name": None, "language": "de"}),
+    ],
+)
+def test_room_labels_in_five_languages(text, expected):
+    assert room_label(text) == expected
+
+
+def test_a_text_without_a_room_word_is_not_a_room_label():
+    assert room_label("T101") is None
+    assert room_label("PROCESS HALL") is None
+    assert room_label("") is None
+
+
+@pytest.mark.parametrize(
+    ("block", "kind", "language"),
+    [
+        ("KLEP_VLINDER", "valve", "nl"),
+        ("VERLOOPSTUK", "reducer", "nl"),
+        ("REDUCER_CONC", "reducer", "en"),
+        ("TANK_V", "tank", "en"),
+        ("POMP", "pump", "nl"),
+        ("SCHAKELKAST", "panel", "nl"),
+        ("НАСОС", "pump", "ru"),
+        ("VANA_KELEBEK", "valve", "tr"),
+    ],
+)
+def test_block_names_say_their_kind(block, kind, language):
+    row = equipment_kind(block)
+    assert row["kind"] == kind and row["language"] == language
+
+
+def test_an_anonymous_block_has_no_kind():
+    assert equipment_kind("*U12") is None
+    assert equipment_kind(None) is None