feat(mech): six mech_* critique focuses, the mech pack, lean 60, aliases and the counts

The four track-B/G branches are merged; this is the integration that makes the 25 new tools one surface instead of four. - engineering/mech/critique.py: the six focuses of spec 13, dispatched the way the P&ID ones are. One index per critique run, shared through run_critique's context, so six focuses cost one read of the drawing; a drawing with no ACADMCP_MECH payload yields nothing at all, which is what keeps focus=None cheap for a P&ID sheet or a plain DXF. Each focus has a positive and a negative fixture. Two narrowings are in the module docstring rather than hidden: mech_view_misaligned checks the projection axis and not the quadrant, because the pinned payload carries no projection angle to check it against, and mech_duplicate_dimension catches two dimensions in the same place rather than a semantic restatement, because no engine exposes what a dimension measured. - The index reads what the tools actually write, not only the plan's fixture shape. mech_part_draw anchors its part payload on a POINT (layer MECH) and lists every drawn view under "views"; the plan's index read INSERT/CIRCLE only and one "view" per payload, so it was silent on every part the server draws. It now reads POINT too, expands "views" into one entry per drawn view (the section check looks in the section's own WCS box, the alignment check compares frame_bbox centres), and pages entity_list instead of one call. Test: a part drawn by draw_part + add_view is read and passes all six; the same part with its hatch erased is reported. - Live type names, measured on AutoCAD 2026 (2026-09-23, scratch document, closed): ObjectName AcDbBlockReference -> BLOCKREFERENCE, AcDbRotatedDimension -> ROTATEDDIMENSION, AcDbAlignedDimension -> ALIGNEDDIMENSION, AcDbPoint -> POINT with GetBoundingBox = the point. The index reads BLOCKREFERENCE as an INSERT and any *DIMENSION as a dimension; a wrapper test reports the ezdxf entities under exactly those measured names. - mech_thread_unrepresented uses the view engine's own MINOR_RATIO, and checks the thin line ISO 6410 draws: the minor diameter of an external thread, the major of an internal one. - mech_bom_balloon_mismatch: identical parts share one balloon (ISO 6433 balloons a parts-list row), so a second M12x60 is covered by the first one's balloon instead of reported. - TOOL_PACK_NAMES has "mech" (the 14 tools of SECTIONS 21-23). SECTION 24 stays core: a frame, a title block, a parts list and an xref are universal drafting, not a vertical. Lean gains five and reaches 60 (54 with TOOL_PACKS=core). - _GROUP_TAG_PRIORITY gains sheet directly after mech; the mech group label becomes "mechanical". SECTION 24's last four tools (xref_attach, xref_manage, image_attach, drawing_export_dwg) now carry the sheet tag, so group, pack and SECTION are one list: 229 tools in 25 groups, and engineering/blocks/entity_creation/drawing return to their pre-SECTION-24 sizes. - Ten golden tuning cases, two of them Turkish (with the diacritic spellings added to the alias records next to the ASCII-folded ones). The shared AutoCAD command set needed no change: the merge had already resolved TABLE, REVCLOUD, SECTIONPLANE, INSERT, ARRAY and SAVEAS, and nothing is stale. - Inventory regenerated, the frozen group-size snapshot retaken from the live registry, and the README release-snapshot / pack / lean figures taken from scripts/check_doc_numbers.py rather than typed. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
2026-09-23 12:48:44 +03:00
parent a6c9c0d927
commit 3b033033f9
11 changed files with 1202 additions and 62 deletions
@@ -1,6 +1,6 @@
 """Golden query set for tool discovery: English in, one right tool out.

-Eighty-one cases (66 tuning + 15 holdout) split into a **tuning** set and a
+Ninety-one cases (76 tuning + 15 holdout) split into a **tuning** set and a
 **holdout** set. The split is
 the point of the file. Ranking work is measured against
 :data:`TUNING_CASES` only; :data:`HOLDOUT_CASES` were written at the same time,
@@ -174,6 +174,22 @@ TUNING_CASES: tuple[GoldenCase, ...] = (
        "counting",
        risk="read",
    ),
+    # v1.6 tracks B + G — the mechanical part drawer and the sheet standard.
+    # Written before the merged alias records were measured against them; a
+    # miss here is fixed by adding vocabulary to that tool's record in
+    # discovery/aliases.py, never by moving the expectation. Two Turkish
+    # queries are in deliberately: this shop searches in Turkish, and the
+    # alias corpus is the only place that vocabulary can live.
+    GoldenCase("XATTACH", "xref_attach", "command"),
+    GoldenCase("IMAGEATTACH", "image_attach", "command"),
+    GoldenCase("draw a stepped shaft from a segment list", "mech_part_draw", "paraphrase"),
+    GoldenCase("add a section view of the part", "mech_view_add", "paraphrase"),
+    GoldenCase("kaynak sembolü", "weld_symbol", "synonym"),
+    GoldenCase("yüzey pürüzlülüğü", "surface_texture", "synonym"),
+    GoldenCase("iso 5457 sheet frame", "sheet_frame", "synonym"),
+    GoldenCase("put an m12 hex bolt on the drawing", "std_part_insert", "paraphrase"),
+    GoldenCase("draw the parts list table on the sheet", "bom_table", "paraphrase"),
+    GoldenCase("save this drawing as a dwg", "drawing_export_dwg", "paraphrase"),
 )


@@ -0,0 +1,361 @@
+"""Six mechanical focuses, each with a positive and a negative fixture.
+
+All six are silent on a drawing with no ACADMCP_MECH payload on it, so
+`focus=None` stays cheap for a P&ID sheet or a plain DXF.
+
+A fixture writes the payload onto a small CIRCLE on layer 0 rather than onto a
+block reference. The index reads INSERT and CIRCLE alike (a balloon is a circle
+with a leader), and a circle keeps the fixtures free of block definitions —
+what is under test here is the reading, not the drawing.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from engineering.layers import ensure_engineering_layers
+from engineering.mech.critique import (
+    MECH_FOCUSES,
+    build_index,
+    has_mech_content,
+    issues_for,
+)
+from engineering.mech.xdata import APP_ID, to_values
+from engineering.plan_spec import ALL_CRITIQUE_FOCUSES
+
+pytestmark = pytest.mark.asyncio
+
+SHAFT = {
+    "name": "shaft",
+    "material": "steel",
+    "segments": [{"length": 60.0, "d_outer": 40.0, "d_inner": 20.0}],
+    "features": [],
+}
+
+
+async def _anchor(backend, payload, x=0.0, y=0.0):
+    ent = await backend.entity_create_circle(x, y, 0.5, layer="0")
+    await backend.entity_set_xdata(ent.handle, APP_ID, to_values(payload))
+    return ent.handle
+
+
+def _focus(index, name):
+    return issues_for(name, index)
+
+
+async def test_the_six_focuses_are_the_spec_ones_and_are_in_the_closed_enum():
+    assert MECH_FOCUSES == (
+        "mech_missing_centreline",
+        "mech_unhatched_section",
+        "mech_view_misaligned",
+        "mech_duplicate_dimension",
+        "mech_thread_unrepresented",
+        "mech_bom_balloon_mismatch",
+    )
+    for focus in MECH_FOCUSES:
+        assert focus in ALL_CRITIQUE_FOCUSES
+
+
+async def test_every_focus_is_silent_on_a_drawing_with_no_mechanical_content(backend):
+    """A circle with no centre mark, two identical dimensions and no hatch —
+    every trigger present, and not one issue, because nothing on the sheet
+    claims to be a mechanical part."""
+    await ensure_engineering_layers(backend)
+    await backend.entity_create_circle(0, 0, 10, layer="GEOMETRY")
+    await backend.dimension_linear(0, 0, 100, 0, 50, 20, layer="DIM")
+    await backend.dimension_linear(0, 0, 100, 0, 50, 20, layer="DIM")
+    index = await build_index(backend)
+    assert has_mech_content(index) is False
+    for focus in MECH_FOCUSES:
+        assert _focus(index, focus) == []
+
+
+async def test_missing_centreline_fires_on_a_bare_circle(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT})
+    await backend.entity_create_circle(100.0, 100.0, 10.0, layer="GEOMETRY")
+    issues = _focus(await build_index(backend), "mech_missing_centreline")
+    assert len(issues) == 1
+    assert issues[0].focus == "mech_missing_centreline"
+    assert "centre mark" in issues[0].message
+
+
+async def test_missing_centreline_is_quiet_once_the_cross_is_drawn(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT})
+    await backend.entity_create_circle(100.0, 100.0, 10.0, layer="GEOMETRY")
+    await backend.entity_create_line(87.0, 100.0, 113.0, 100.0, layer="CENTER")
+    await backend.entity_create_line(100.0, 87.0, 100.0, 113.0, layer="CENTER")
+    assert _focus(await build_index(backend), "mech_missing_centreline") == []
+
+
+async def test_unhatched_section_fires_on_a_section_view_with_no_hatch(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(
+        backend,
+        {"v": 1, "kind": "part", "id": "P1", "view": "section", "part": SHAFT},
+        x=0.0,
+        y=0.0,
+    )
+    issues = _focus(await build_index(backend), "mech_unhatched_section")
+    assert len(issues) == 1
+    assert issues[0].severity == "error"
+    assert "hatched cut face" in issues[0].message
+
+
+async def test_unhatched_section_is_quiet_when_the_cut_face_is_hatched(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(
+        backend,
+        {"v": 1, "kind": "part", "id": "P1", "view": "section", "part": SHAFT},
+        x=0.0,
+        y=0.0,
+    )
+    await backend.entity_create_hatch(
+        "ANSI31", [[10.0, 10.0], [20.0, 10.0], [20.0, 20.0], [10.0, 20.0]], layer="HATCH"
+    )
+    assert _focus(await build_index(backend), "mech_unhatched_section") == []
+
+
+async def test_view_misaligned_fires_when_a_side_view_leaves_the_projection_axis(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(
+        backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT}, 0.0, 0.0
+    )
+    await _anchor(
+        backend, {"v": 1, "kind": "part", "id": "P1", "view": "side", "part": SHAFT}, 150.0, 5.0
+    )
+    issues = _focus(await build_index(backend), "mech_view_misaligned")
+    assert len(issues) == 1
+    assert issues[0].detail["axis"] == "y"
+    assert issues[0].detail["delta_mm"] == 5.0
+
+
+async def test_view_misaligned_is_quiet_on_an_aligned_pair(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(
+        backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT}, 0.0, 0.0
+    )
+    await _anchor(
+        backend, {"v": 1, "kind": "part", "id": "P1", "view": "side", "part": SHAFT}, 150.0, 0.0
+    )
+    assert _focus(await build_index(backend), "mech_view_misaligned") == []
+
+
+async def test_duplicate_dimension_fires_on_the_same_dimension_twice(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT})
+    await backend.dimension_linear(0, 0, 60, 0, 30, -20, layer="DIM")
+    await backend.dimension_linear(0, 0, 60, 0, 30, -20, layer="DIM")
+    issues = _focus(await build_index(backend), "mech_duplicate_dimension")
+    assert len(issues) == 1
+    assert len(issues[0].handles) == 2
+
+
+async def test_duplicate_dimension_is_quiet_on_two_different_dimensions(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT})
+    await backend.dimension_linear(0, 0, 60, 0, 30, -20, layer="DIM")
+    await backend.dimension_linear(0, 0, 40, 0, 20, -35, layer="DIM")
+    assert _focus(await build_index(backend), "mech_duplicate_dimension") == []
+
+
+THREADED = {
+    "name": "stud",
+    "material": "steel",
+    "segments": [{"length": 60.0, "d_outer": 20.0}],
+    "features": [{"kind": "thread", "id": "t1", "designation": "M20x1.5", "segment": 0}],
+}
+
+
+async def test_thread_unrepresented_fires_when_only_the_major_diameter_is_drawn(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "side", "part": THREADED})
+    await backend.entity_create_circle(0.0, 0.0, 10.0, layer="GEOMETRY")
+    issues = _focus(await build_index(backend), "mech_thread_unrepresented")
+    assert len(issues) == 1
+    assert issues[0].detail["minor_mm"] == 16.0
+    assert "ISO 6410" in issues[0].message
+
+
+async def test_thread_unrepresented_is_quiet_once_the_minor_circle_is_drawn(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "side", "part": THREADED})
+    await backend.entity_create_circle(0.0, 0.0, 10.0, layer="GEOMETRY")
+    await backend.entity_create_arc(0.0, 0.0, 8.0, 0.0, 270.0, layer="GEOMETRY")
+    assert _focus(await build_index(backend), "mech_thread_unrepresented") == []
+
+
+BOLT = {
+    "v": 1,
+    "kind": "std_part",
+    "designation": "ISO 4014 - M12x60",
+    "standard": "ISO 4014",
+    "size": "M12x60",
+    "qty": 1,
+    "material": "8.8",
+}
+
+
+async def test_bom_balloon_mismatch_fires_on_a_balloon_pointing_at_nothing(backend):
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, BOLT, 0.0, 0.0)
+    await _anchor(backend, {"v": 1, "kind": "balloon", "item": 1, "targets": ["DEAD"]}, 40.0, 40.0)
+    issues = _focus(await build_index(backend), "mech_bom_balloon_mismatch")
+    assert any("not a part on this sheet" in issue.message for issue in issues)
+
+
+async def test_bom_balloon_mismatch_fires_on_a_part_with_no_balloon(backend):
+    await ensure_engineering_layers(backend)
+    bolt = await _anchor(backend, BOLT, 0.0, 0.0)
+    await _anchor(
+        backend, {**BOLT, "size": "M16x60", "designation": "ISO 4014 - M16x60"}, 60.0, 0.0
+    )
+    await _anchor(backend, {"v": 1, "kind": "balloon", "item": 1, "targets": [bolt]}, 40.0, 40.0)
+    issues = _focus(await build_index(backend), "mech_bom_balloon_mismatch")
+    assert any("has no balloon" in issue.message for issue in issues)
+
+
+async def test_bom_balloon_mismatch_fires_when_the_declared_quantity_disagrees(backend):
+    await ensure_engineering_layers(backend)
+    first = await _anchor(backend, {**BOLT, "qty": 4}, 0.0, 0.0)
+    await _anchor(backend, {"v": 1, "kind": "balloon", "item": 1, "targets": [first]}, 40.0, 40.0)
+    issues = _focus(await build_index(backend), "mech_bom_balloon_mismatch")
+    assert any("declares 4" in issue.message for issue in issues)
+
+
+async def test_bom_balloon_mismatch_is_quiet_on_a_matched_sheet(backend):
+    await ensure_engineering_layers(backend)
+    bolt = await _anchor(backend, BOLT, 0.0, 0.0)
+    await _anchor(backend, {"v": 1, "kind": "balloon", "item": 1, "targets": [bolt]}, 40.0, 40.0)
+    assert _focus(await build_index(backend), "mech_bom_balloon_mismatch") == []
+
+
+async def test_the_dispatch_entries_share_one_index_per_run(backend):
+    """Six focuses must cost one read of the drawing, like the P&ID ones."""
+    from engineering.mech.critique import MECH_DISPATCH
+
+    await ensure_engineering_layers(backend)
+    await _anchor(backend, {"v": 1, "kind": "part", "id": "P1", "view": "front", "part": SHAFT})
+    shared: dict = {}
+    for focus in MECH_FOCUSES:
+        check = MECH_DISPATCH[focus]
+        assert check.needs_shared is True
+        await check(backend, shared)
+    assert list(shared) == ["mech_index"]
+
+
+# ── the payloads the real writers put on the drawing ────────────────────────
+#
+# The fixtures above anchor a hand-written payload on a CIRCLE. The tools do
+# not: mech_part_draw anchors its part payload on a POINT (layer MECH) and
+# lists every view it drew under "views", std_part_insert writes onto the
+# INSERT, balloon_add onto the balloon's circle. An index that read only the
+# fixtures' shape would be silent on every drawing the server actually makes.
+
+REAL_SHAFT = {
+    "kind": "revolved",
+    "name": "stud",
+    "material": "steel",
+    "segments": [
+        {"length": 30.0, "d_outer": 20.0},
+        {"length": 50.0, "d_outer": 30.0, "d_inner": 10.0},
+    ],
+    "features": [
+        {"kind": "thread", "id": "t1", "designation": "M20x1.5", "segment": 0, "length": 20.0}
+    ],
+}
+CROSS_SECTION = {"p1": [50.0, -30.0], "p2": [50.0, 30.0]}
+
+
+async def _real_part(backend):
+    from engineering.mech.draw import add_view, draw_part
+    from engineering.mech.part import build_part
+
+    drawn = await draw_part(backend, build_part(REAL_SHAFT), views=("front", "side"))
+    await add_view(backend, drawn["part_id"], "section", plane=CROSS_SECTION)
+    return drawn["part_id"]
+
+
+async def test_a_part_drawn_by_the_tools_is_read_and_passes_every_focus(backend):
+    part_id = await _real_part(backend)
+    index = await build_index(backend)
+    assert has_mech_content(index) is True
+    assert [r["handle"] for r in index["records"]] == [part_id]
+    assert [v["kind"] for v in index["views"]] == ["front", "side", "section"]
+    for focus in MECH_FOCUSES:
+        assert _focus(index, focus) == [], focus
+
+
+async def test_a_real_section_whose_hatch_was_erased_is_reported(backend):
+    part_id = await _real_part(backend)
+    for hatch in await backend.entity_list(type_filter="HATCH"):
+        await backend.entity_delete(hatch.handle)
+    issues = _focus(await build_index(backend), "mech_unhatched_section")
+    assert len(issues) == 1
+    assert issues[0].handles == [part_id]
+    assert issues[0].detail["view"] == 2
+
+
+async def test_identical_parts_share_one_balloon(backend):
+    """ISO 6433 balloons a parts-list row: four identical bolts, one item."""
+    await ensure_engineering_layers(backend)
+    first = await _anchor(backend, BOLT, 0.0, 0.0)
+    await _anchor(backend, BOLT, 60.0, 0.0)
+    await _anchor(backend, {"v": 1, "kind": "balloon", "item": 1, "targets": [first]}, 40.0, 40.0)
+    assert _focus(await build_index(backend), "mech_bom_balloon_mismatch") == []
+
+
+async def test_the_index_reads_past_the_first_page_of_entities(backend):
+    """entity_list defaults to 200; a payload on entity 251 must still count."""
+    await ensure_engineering_layers(backend)
+    for i in range(250):
+        await backend.entity_create_line(float(i), 0.0, float(i), 5.0, layer="GEOMETRY")
+    await _anchor(backend, BOLT, 0.0, 50.0)
+    assert has_mech_content(await build_index(backend)) is True
+
+
+class _LiveTypeNames:
+    """The ezdxf backend reporting entity types the way the live engine does.
+
+    ComBackend names a type from its ActiveX ObjectName with ``AcDb`` stripped
+    and upper-cased; measured on AutoCAD 2026 (2026-09-23), a block reference
+    reads back as BLOCKREFERENCE and a linear dimension as ROTATEDDIMENSION.
+    Only those two renames are applied -- POINT, CIRCLE, LINE and HATCH are
+    already the same on both engines.
+    """
+
+    _RENAME = {"INSERT": "BLOCKREFERENCE", "DIMENSION": "ROTATEDDIMENSION"}
+
+    def __init__(self, inner):
+        self._inner = inner
+
+    def __getattr__(self, name):
+        return getattr(self._inner, name)
+
+    async def entity_list(self, *args, **kwargs):
+        import dataclasses
+
+        return [
+            dataclasses.replace(ent, type=self._RENAME.get(ent.type, ent.type))
+            for ent in await self._inner.entity_list(*args, **kwargs)
+        ]
+
+
+async def test_the_live_engine_type_names_are_read(backend):
+    """A standard part on an INSERT and two stacked dimensions, seen through
+    the live engine's type names: the payload is still read and the duplicate
+    still found."""
+    await ensure_engineering_layers(backend)
+    ref = await backend.entity_create_circle(0.0, 0.0, 1.0, layer="0")
+    await backend.block_create_from_entities("T15_BOLT", [ref.handle], 0.0, 0.0)
+    bolt = await backend.block_insert("T15_BOLT", 0.0, 0.0, 1.0, 1.0, 0.0, None, "GEOMETRY")
+    await backend.entity_set_xdata(bolt.handle, APP_ID, to_values(BOLT))
+    await backend.dimension_linear(0, 0, 60, 0, 30, -20, layer="DIM")
+    await backend.dimension_linear(0, 0, 60, 0, 30, -20, layer="DIM")
+
+    index = await build_index(_LiveTypeNames(backend))
+    assert [r["handle"] for r in index["records"]] == [bolt.handle]
+    assert {e.type for e in index["entities"]} >= {"BLOCKREFERENCE", "ROTATEDDIMENSION"}
+    duplicates = _focus(index, "mech_duplicate_dimension")
+    assert len(duplicates) == 1 and len(duplicates[0].handles) == 2
@@ -8,7 +8,9 @@ surface and nothing else.

 v1.6 tracks B+G add the `mech` pack: SECTION 21's six part-model tools and
 SECTION 22's three standard-parts tools and SECTION 23's five annotation
-symbols - 14 in all.
+symbols - 14 in all. SECTION 24 (the sheet: frames, title blocks, revisions,
+the parts list, balloons, xrefs, images, DWG) stays in `core` - universal
+drafting, not a vertical - and files under its own `sheet` group.
 """

 from __future__ import annotations
@@ -99,6 +101,28 @@ MECH_TOOLS = {
    "hatch_material",
 }

+SHEET_TOOLS = {
+    "sheet_frame",
+    "titleblock_apply",
+    "revision_add",
+    "bom_extract",
+    "bom_table",
+    "balloon_add",
+    "data_extract",
+    "xref_attach",
+    "xref_manage",
+    "image_attach",
+    "drawing_export_dwg",
+}
+
+LEAN_MECH_ESSENTIALS = {
+    "mech_part_draw",
+    "mech_view_add",
+    "mech_dimension_part",
+    "sheet_frame",
+    "titleblock_apply",
+}
+
 LEAN_SETTINGS_ESSENTIALS = {
    "drawing_apply_standard",
    "page_setup_apply",
@@ -130,6 +154,9 @@ def test_pack_registry_names_real_tools_and_only_them():
    assert not (server.PACK_TOOL_NAMES["settings"] & server.PACK_TOOL_NAMES["pid"])
    assert not (server.PACK_TOOL_NAMES["mech"] & server.PACK_TOOL_NAMES["pid"])
    assert not (server.PACK_TOOL_NAMES["mech"] & server.PACK_TOOL_NAMES["settings"])
+    assert not (SHEET_TOOLS & set().union(*server.PACK_TOOL_NAMES.values())), (
+        "SECTION 24 is core drafting, not a vertical pack"
+    )


 async def test_every_pack_member_is_a_registered_tool():
@@ -146,6 +173,7 @@ async def test_core_only_hides_pid_and_settings_but_keeps_styles_and_page_setup(
    assert PID_TOOLS <= disabled
    assert SETTINGS_TOOLS <= disabled
    assert MECH_TOOLS <= disabled
+    assert not (SHEET_TOOLS & disabled)
    assert not (STYLE_TOOLS & disabled), "styles are core drafting essentials"
    assert not (PAGE_SETUP_TOOLS & disabled), "page setup and templates are core"
    assert "block_define" not in disabled and "entity_set_xdata" not in disabled
@@ -194,16 +222,19 @@ async def test_lean_intersects_with_packs(monkeypatch):
 async def test_lean_carries_the_five_settings_essentials_and_nothing_from_the_settings_pack(
    monkeypatch,
 ):
-    """Spec §8.2: lean = 55. The five are core-pack tools, so `TOOL_PACKS=core`
-    leaves them on a lean surface; no environment tool is lean."""
+    """Spec §8.2: lean = 60 (55 + the five mechanical/sheet essentials). The
+    five settings essentials are core-pack tools, so `TOOL_PACKS=core` leaves
+    them on a lean surface; no environment tool is lean."""
    assert LEAN_SETTINGS_ESSENTIALS <= server.LEAN_TOOL_NAMES
+    assert LEAN_MECH_ESSENTIALS <= server.LEAN_TOOL_NAMES
    assert not (SETTINGS_TOOLS & server.LEAN_TOOL_NAMES)
-    assert len(server.LEAN_TOOL_NAMES) == 55
+    assert len(server.LEAN_TOOL_NAMES) == 60
    monkeypatch.setattr(config.settings, "tool_packs", "core")
    info = await server._apply_tool_profile("lean")
    disabled = set(info["disabled_tools"])
    assert not (LEAN_SETTINGS_ESSENTIALS & disabled)
-    assert info["enabled_count"] == 55 - 3, "lean minus the three pid tools"
+    assert not ({"sheet_frame", "titleblock_apply"} & disabled), "sheet tools are core"
+    assert info["enabled_count"] == 60 - 6, "lean minus the three pid and three mech tools"


 async def test_the_three_track_e_sections_file_under_their_own_groups():
@@ -213,8 +244,9 @@ async def test_the_three_track_e_sections_file_under_their_own_groups():
    assert set(groups["styles"]) == STYLE_TOOLS
    assert set(groups["page_setup"]) == PAGE_SETUP_TOOLS
    assert set(groups["environment"]) == SETTINGS_TOOLS
-    assert set(groups["mech"]) == MECH_TOOLS
-    assert len(groups) == 24
+    assert set(groups["mechanical"]) == MECH_TOOLS
+    assert set(groups["sheet"]) == SHEET_TOOLS
+    assert len(groups) == 25


 async def test_system_about_reports_packs():
@@ -495,7 +495,7 @@ async def test_tool_groups_is_byte_identical_to_the_source_declared_grouping():


 async def test_tool_group_sizes_are_unchanged():
-    """Frozen snapshot of the surface (229 tools, 24 groups).
+    """Frozen snapshot of the surface (229 tools, 25 groups).

    Taken before @cad_tool landed at 131 tools; `batch` moved 2 -> 3 when
    v1.5.0's `cad_batch` joined `entity_batch_create`/`entity_batch_modify`, and
@@ -565,26 +565,43 @@ async def test_tool_group_sizes_are_unchanged():
    are tagged `engineering` and `mech`; with `mech` ranked ahead of
    `engineering` in `_GROUP_TAG_PRIORITY` they file under `mech` (14 in all,
    exactly `PACK_TOOL_NAMES["mech"]`) and leave `engineering` untouched.
+
+    Two groups appeared with v1.6's tracks B and G — `mechanical` (14,
+    SECTIONS 21-23: the part drawer, the standard-parts catalogue and the ISO
+    annotation symbols) and `sheet` (11, SECTION 24: frames, title blocks,
+    revisions, the parts list, balloons, xrefs, images and DWG). Both tags are
+    ranked directly after `pid` in `_GROUP_TAG_PRIORITY`, so a part tool that
+    also carries `create` and an annotation tool that also carries `dimension`
+    file under their own section. `mechanical` is exactly
+    `PACK_TOOL_NAMES["mech"]` (the `mech` label above was renamed when the
+    integration task gave the section its full name); `sheet` is core-pack,
+    because a frame, a title block, a parts list and an xref are universal
+    drafting. The integration also tagged SECTION 24's last four tools
+    (`xref_attach`, `xref_manage`, `image_attach`, `drawing_export_dwg`) with
+    `sheet`, so pack, group and SECTION are one list again: `engineering`
+    returned 17 -> 10, `blocks` 11 -> 9, `entity_creation` 19 -> 18 and
+    `drawing` 12 -> 11 — every one of them its pre-SECTION-24 value.
    """
    sizes = {label: len(names) for label, names in (await server._tool_groups()).items()}
    assert sizes == {
        "analysis": 12,
        "batch": 3,
-        "blocks": 11,
+        "blocks": 9,
        "corner_ops": 4,
        "dimensions": 5,
-        "drawing": 12,
-        "engineering": 17,
-        "entity_creation": 19,
+        "drawing": 11,
+        "engineering": 10,
+        "entity_creation": 18,
        "entity_modification": 16,
        "entity_query": 9,
        "environment": 22,
        "layers": 14,
        "layouts": 12,
-        "mech": 14,
+        "mechanical": 14,
        "page_setup": 6,
        "pid": 9,
        "premium": 12,
+        "sheet": 11,
        "solids": 5,
        "styles": 10,
        "system": 7,