Two review findings on pid_line_draw, both root-caused:
1. existing_pid_lines() filtered entity_list(type_filter="LWPOLYLINE") and
tested info.type == "LWPOLYLINE". A live LWPOLYLINE's ActiveX ObjectName
is AcDbPolyline (the repo's own 2026-08-06 measurement), which the COM
engine reports as POLYLINE, so on live AutoCAD every auto-built number was
seq 1, crossings always 0 and port_reuse always []. The reader now lists
without a type filter and accepts {LWPOLYLINE, POLYLINE, 2DPOLYLINE} plus
LINE — the same set the Task 14 graph reader keeps. The COM _entity_info
polyline branch matched only the DXF-flavoured "AcDbLWPolyline", so a live
LWPOLYLINE never got `points` either; it now accepts both spellings (with
the OCS normalisation), which is what makes the crossing count real there.
2. resolve_endpoint() applied only x_scale, so a mirrored INSERT
(entity_mirror writes y_scale = -1) resolved its port to a point off the
symbol and the line was drawn through the pump body. transform_port takes
an optional y_scale (default: uniform, signature unchanged) and applies the
full reflect-then-rotate transform to point, direction and radius; a
stretched symbol (|x_scale| != |y_scale|) has no circle for a radial port
and is refused with a clear ValueError instead of a silent wrong number.
Tests: mirror about both axes resolves onto the real geometry, a stretched
copy is refused, and a fake-COM AcDbPolyline probe sees the existing line
with its seq, vertices and from-ref.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Nozzle stubs started at the bounding-box edge, so on a dished head, a
hopper's sloped wall or a cone roof they floated off the vessel (default
horizontal_vessel N3/N4 by 0.8 mm, reactor N3/N4 by 0.06 mm, unbounded for
user fractions). The port now stays STUB outside the bbox and the stub is
drawn from there in to where its axis-aligned line meets the outline, via a
new geometry.scan_hits helper; jacketed reactors' stubs pass through the
jacket to the wall.
validate_vessel_params refuses height <= width for vertical capsules
(vertical_vessel, column, reactor), width <= height for horizontal_vessel
and height <= width/6 for a cone-roof tank: those folded the heads through
each other and produced geometry outside the declared bbox. Unknown keys
inside a nozzle dict are refused naming nozzles[i] and the key, like the
top-level parameters already were.
Tests: a fuzz over every accepted vessel shape x 28 nozzle positions checks
the declared bbox and that each stub's inner end lies on the outline (exact
point-to-arc/segment distance); the default-symbol repros and the refusals
are pinned. 137 of the new cases fail against the previous module.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Task 9 of the v1.6 P&ID plan: engineering/pid/symbols_equipment.py fills
the stub with three ISO 10628-2 families registered on import — rotating
(centrifugal_pump, pd_pump, compressor, fan, agitator, ejector), heat
(shell_tube_hx, plate_hx, air_cooler, fired_heater) and misc inline
fittings (filter, strainer_y, reducer with shape=concentric|eccentric,
flange_pair, spectacle_blind, orifice_plate with a signal port,
drain_vent). Every port sits on the declared bbox edge and every symbol
carries the TAG/DESC attribute pair; the catalogue harness now covers
103 specs.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Two authoring slips in the valve x actuator composition:
- The diaphragm actuator's stem stopped at y=4 while the dome's flat base
sat at y=6, so the canonical control-valve symbol (PID_VALVE_*_DIAPHRAGM,
9 catalogue entries) shipped with its dome floating 2 mm above the stem.
- Actuators were placed at a fixed y=4 regardless of the body, so on the
needle body (top 5.6) the piston/motor/solenoid glyphs were drawn over
the knob and the hand bar across the needle's stem; the stem line(0,0,0,4)
also duplicated the needle's own axial line (and the butterfly disc).
Placement is now body-relative: `_body` reports `axis_top` (where its own
geometry on x=0 ends) and the stem runs from there to the glyph base at
`body_top + STEM_CLEARANCE`; the diaphragm dome's base is the stem top
(base + DIAPHRAGM_YOKE), and the FAIL attribute follows the glyph base.
The reference 8x4 bodies keep their published numbers (globe+diaphragm
signal at y=9.0, bbox top 9.0).
Tests: per-combination check that the stem starts at the body's derived
axis top, the glyph's lowest edge equals the stem top, the glyph clears
the body, and the signal port is the topmost edge; plus a catalogue-wide
no-duplicate-primitives gate. 33 combinations fail on the old geometry.
The plan's Step 3 snippet is synced with the fixed module.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
build_instrument drew a circle for every type, so `computer` shipped as
circle + hexagon and `plc` as circle + square + diamond (10 of the 20 bubble
blocks wrong, and the circle poked 0.67 mm outside the hexagon's flat top).
Spec 4.4: discrete = circle; dcs = circle inside a square; computer =
hexagon; plc = diamond inside a square. The outline is now chosen per type.
Location lines were always drawn from -r to +r, overshooting the hexagon's
slanted sides by 0.46 mm at y=+/-0.8 and the circle's chord by 0.06 mm.
They now end on the outline (`_bubble_half_width`): chord for the circle,
full width for the square, `r - |y| / tan 60` for the hexagon.
Tests now assert the exact primitive list per type and that every location
line stays on/inside its outline (both fail against the previous code).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Three ways `engineering/pid/lines.py` could emit a silent wrong result or
an opaque crash instead of an honest refusal:
- `format_line_number` only recognised a token that was exactly `{field}`;
`P-{seq:04d}`, `{size}"-{service}` or `{bogus}x` were copied verbatim,
braces and all, into the line number. Tokens are now parsed with
`string.Formatter`: one named known field per token, a format spec is
honoured (`{seq:04d}` -> `0007`), literal decoration around the field
survives with it and drops out with it, and conversions, positional
fields, multi-field tokens, unbalanced braces and specs the value cannot
take are all refused by token name.
- `route` never checked finiteness: a NaN `end` collapsed the U candidate
to a valid two-point "straight" path ending at the stub point. Every
coordinate of start/end/waypoints and the stub are now checked and the
refusal names the offending `end.x` / `waypoints[1].y` / stub.
- A non-axis port direction (45.0, 90.5, nan) raised `KeyError` from the
AXIS lookup. `axis_direction()` now normalises with a 1e-6 deg tolerance
for engine drift and otherwise raises ValueError naming `start_dir` /
`end_dir` and how to resolve it (rotate to a multiple of 90 or pass
waypoints).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Every one of these was reported ok/clean to the caller while being wrong.
Silently wrong numbers
- selection_filter(min_area) read `entity.dxf.get("area", 0.0)` for SOLID,
TRACE and HATCH, none of which carry that attribute, so every hatch
measured 0.0. A 1600 mm^2 hatch was excluded by min_area=1.0 while
`filtered_by` asserted the filter had run, and COM (which reads ActiveX
.Area) returned a different selection for the same call. It now answers
from the measurement `entity_measure` uses, so the two cannot disagree.
- Every headless dimension rendered through ezdxf's bare `Standard` style:
1.0 mm text with a comma decimal marker, against ISO 3098's 2.5 mm minimum
and ISO 129's point -- while the document header itself said $DIMTXT 2.5.
`ezdxf.new(setup=True)` is not the fix; measured, it renders a 100 mm
dimension as "10000". The attributes are now stored explicitly.
- Saving writes `dimrnd = 0.0` onto the Standard style, and ezdxf applies
`xround(value, dimrnd)` whenever the attribute is present at all --
`xround(33.333, 0.0)` is 33. So on any reopened file, including one this
server saved, every dimension was rounded to a whole unit before DIMDEC
formatted it: a 12.75 mm feature dimensioned 13. AutoCAD means DIMRND 0 as
*no* rounding; the sentinel is now discarded at every load site, and a real
0.5 mm rounding is left alone.
- The DIM* header fold gave out-of-range values teeth they did not have when
they died in the header: dim_decimals=-1 returned ok and then killed the
next dimension with `ValueError: Format specifier missing precision` from
inside ezdxf, and 40 printed forty digits of float noise onto the sheet.
Ranges are now AutoCAD's own (DIMDEC 0-8, DIMZIN 0-15, lengths positive).
Security
- security.py recorded the policy as "sanitize_command and sanitize_lisp each
have exactly ONE caller ... the policy is scoped to the CHANNEL". The
premise was false. `_ensure_linetype_loaded` and `ComBackend.linetype_load`
build `_-LINETYPE _LOAD {name} {file}` and hand it to SendCommand, which
treats a newline and ';' as segment separators -- so a `linetype=` argument
carrying either injected further AutoCAD commands, and the 36-verb denylist
never saw that channel. Guarded with the DXF symbol-name rule (the
injection characters fall out of it rather than being enumerated) plus
validate_path for the file argument, which was also the one path-taking
tool reaching the filesystem unchecked. The policy comment is corrected.
Gates that could not see
- drawing_critique returned zero issues on a quarantined document: all seven
checks wrapped their backend call in a bare `except Exception`. CLAUDE.md
rule 7 makes that call the gate an agent is told to trust. Only the
quarantine now escapes; an ordinary broken check still degrades.
`_check_dimension_legibility` also read `_doc` directly from the event loop
thread, missing the gate and performing exactly the unsynchronised access
the quarantine exists to prevent. `construction_clear` answered
"deleted: 0" -- there was nothing to clear -- for the same reason.
- The iso128 focus checked layer lineweights only, so a sheet lettered at
1.0 mm critiqued clean. It now reads the effective dimension height and
separator, header-then-style, in the order the renderer resolves.
- check_doc_numbers.py derived five values it never checked, and those were
the ones that had drifted. The collected-test count (README said 1274, the
tree had 1369) and the A/B pass-rate and Fixed columns are now gated.
- benchmarks/README.md's v1.4.0 table was impossible on its face -- 21
passing plus 5 fixed is 26, not 24 -- and contradicted the report it
linked, because `ab-v1.4.0-vs-v1.5.0.json` was regenerated from a tree that
already carried the dimension fixes and so never measured the v1.5.0 tag.
Replaced with a real run: ab-v1.4.0-vs-v1.5.1.json, 21/26 -> 26/26.
Release gate
- release.yml ran one ubuntu/3.11 lane, so a Windows-only defect could reach
PyPI with no Windows job having executed. That is not hypothetical: v1.5.0
shipped `except pywintypes.com_error` raising NameError wherever pywin32 is
absent. It now runs the same three lanes as ci.yml, Windows included.
1368 passed, 1 xfailed. ruff clean. Tool inventory and all 16 gated document
numbers match the tree.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
**COM discarded areas it had already read.** `entity_measure` fell back to
rebuilding geometry from `.Coordinates` when `.Area` *or* `.Length` was
missing, coupling two independent property reads. HATCH, REGION and 3DSOLID
expose `.Area` and neither of the others, so the fallback fired, found no
vertices, and raised "AutoCAD reported neither an area nor usable vertices" --
while holding the area. Those are the exact types the README sells the COM
backend on. Now only a missing `.Area` triggers the fallback; an absent
perimeter is reported as `None` with `perimeter_exact: False` instead of being
invented, which also removes a `round(None, 6)` TypeError waiting for the first
type that answers `.Area` and nothing else.
**A plain square hatch reported itself self-intersecting.** `ezdxf.path
.flattening()` repeats the start point, and `is_self_intersecting` excluded
adjacent edges *by index*, so with the duplicate present the first and last
real edges were cross-tested and registered as crossing. Measured: a 40x40
SOLID hatch came back `area: 1600.0, self_intersecting: True`. A closed loop
now answers the same whether or not it carries its closing vertex, and a real
bowtie is still caught (`area: 0.0, self_intersecting: True`).
**The bowtie warning never fired on the live backend.** `self_intersecting` was
only computed inside the COM fallback, so an LWPOLYLINE bowtie -- which has
both `.Area` and `.Length` and never reaches it -- returned `area: 0.0,
self_intersecting: null`. The confident zero this field exists to flag, going
out unflagged. It is now computed on the normal path too.
Also corrects a docstring written earlier today in `contracts/analysis.py`
claiming the live backend "asks AutoCAD for `.Area`, which has already applied
the [hatch island] style". Whether ActiveX's hatch area applies the style is
not verified against a live seat, and the method could not measure a hatch at
all. It now says so.
The ActiveX member profiles behind the COM tests are assumptions, not facts,
and the tests say so; a live seat settles them. `.Circumference` for CIRCLE and
`.Perimeter` for REGION are deliberately NOT added here -- writing more members
from the reference is what produced four wrong beliefs in v1.4/v1.5.
1267 passed, 1 xfailed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Tool count 131 -> 154; 474 -> 1242 collected tests.
The release exists for two measured reasons. A 149-tool catalog costs a client
~40,300 tokens before it has asked for anything, and a drafter searching the way
drafters think -- FILLET, BPOLY, QSELECT, WBLOCK -- scored df=0 against the stock
index, because those words were simply not in the data.
Discovery and batching
- DISCOVERY_MODE=search replaces the catalog with search_tools + call_tool,
ranked over an AutoCAD command and synonym corpus (discovery/aliases.py) on
top of fastmcp's BM25 index. Measured: 40,305 -> 356 tokens advertised.
- cad_batch runs a step list in one round trip; fields= projects result-heavy
responses. The `core` profile is gone -- discovery replaced it.
Honesty debt (Tier 0)
- OCS/ECS: `extrusion` appeared nowhere in this codebase, so mirrored and
rotated geometry reported coordinates that were quietly wrong. backends/ocs.py
translates at the backend boundary; every tool coordinate is WCS on both
engines, and a tilted plane refuses rather than answering with a number that
looks fine.
- drawing_save_as(fmt="dwg") wrote DXF bytes to a .dwg path. drawing_audit never
repaired. analysis_measure_area shoelaced points the caller typed in.
- ezdxf calls gained a per-call timeout, so one hung call can no longer wedge a
server whose document lock is a single asyncio.Lock.
Architecture
- The 1854-line backend ABC is 19 contract modules; @capability(key, reason=)
makes optional methods declarative and a gate fails on undeclared holes.
- 8 layout/viewport tools, CHSPACE, CAD_PROGID escape hatch.
- Wave A: selection filters, boundary tracing, hatch depth, annotation objects,
measurement -- 13 tools of a planned 39. The REGION and 2D-boolean family was
cut on evidence: add_region() yields zero ACIS bytes and the greiner_hormann
substitute loses 28.2% of the area on a square with one semicircular edge.
Verified against a live AutoCAD 2026, which found four COM defects no amount of
reading would have caught -- AcadPViewport has no ViewCenter, and the line that
set it had been swallowed by a bare except since v1.4.
Benchmark v3 (15 tasks) and what it caught
- v2 scored this server 10/10, which carried no information: every task in it
exercised something the server was built around. Five tasks were added because
they can fail, and three did while being written -- a hatch could not be
measured though the refusal listed HATCH as measurable, the boundary tools and
the measure tool disagreed about the same shape (139.2177 vs 139.2699), and a
circle stored as two bulged vertices measured 0.0.
- Competitor reports are NOT re-scored. They are pinned v1.4 runs against v2 and
were never asked these five questions; the chart shows those rows `not run`.
- Correctness A/B: 21/24 -> 24/24, zero regressions.
Performance, stated plainly
The published v1.4 perf report was recorded on CPython 3.14 and the new one on
3.11.15, so the apparent 2-6x speedup is the interpreter, not this release.
Re-measured on one interpreter, v1.5.0 is 28% slower creating entities and 22%
slower on the 10k roundtrip. Fully attributed: EZDXF_CALL_TIMEOUT=0 restores
v1.4.0's exact numbers. That is the deadlock fix being paid for, the knob is
documented, and winning it back is on the 1.6 roadmap.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
- TOOL_PROFILE=lean|core|full applied in the lifespan via server-level enable/disable; system_about reports the active profile; opt-in solid_* tools are hidden while ENABLE_3D=false
- layouts: layout_list/create/set_current + viewport_create (scaled model viewports) on both backends; drawing_export_pdf(layout=...); ezdxf uses TILEMODE + active-layout binding, COM switches ActiveLayout and restores it
- ISO 286: engineering/fits.py authored IT4-11 + fundamental-deviation tables (1-500 mm; shafts d..p/h/js, holes D..H/JS) with clear out-of-scope errors; dimension_linear/radius/diameter gained fit= resolved from the measured nominal
- tolerances: DIMTM now signed in deviation/limit modes so double-positive fits (p6 +0.035/+0.022) render correctly; legacy positive-magnitude contract preserved
- solids: solid_box/cylinder/extrude/revolve/boolean native on COM (AddBox/AddCylinder/AddRegion+AddExtrudedSolid/AddRevolvedSolid/Boolean); ezdxf reports the honest solid_3d capability boundary
- capability maps: paper_space native, new viewport_render feature, ENABLE_3D-gated solid_3d
- 60 new tests (profiles, layouts, viewports, layout PDF, fits, gating); version pins in tests now read version.__version__
Co-authored-by: Cursor <cursoragent@cursor.com>
ruff format was never run repo-wide; CI now enforces 'ruff format --check', so normalize every module once. No behavior changes.
Co-authored-by: Cursor <cursoragent@cursor.com>
Adds production-grade engineering features and tools: 2D GD&T (feature control frames + datum features) via engineering/gdt.py, ISO‑129 dimension tolerance support (engineering/tolerances.py) and an ezdxf/COM plumbing for toleranced dims, a scalar drawing score + invalidity ratio (engineering/scoring.py) wired into drawing_finalize, in-place entity editors (entity_edit_text/entity_edit_geometry), and a friendly drawing_settings facade. Includes server tool wiring, COM/ezdxf backend implementations, datum-consistency critique, many unit tests, README/CLAUDE/CHANGELOG updates, and a version bump to 1.2.0. Also corrects COM backend capability label (entities_2d).
Audit-driven fixes across the dual backend, the premium workflow, and the
engineering layer. 318 tests, ruff-clean.
Quality gate (the moat):
- drawing_finalize now runs the premium ISO-128 critique in addition to the
8-step validator; leftover construction, non-ISO lineweights, untrimmed
corners, duplicates and dim overlap block the gate (strict_critique fails on
warnings too).
- dim_overlap critique no longer a no-op (dim reference point + bbox fallback);
dim/construction layers resolve from the active layer set (iso13567 too).
Stability / correctness:
- view_screenshot & drawing_export_pdf render headless via Agg (no more
worker-thread SIGSEGV).
- gear tooth profile no longer self-overlaps at high tooth counts; section view
no longer duplicates bore lines; validator keyway heuristic fixed.
- ezdxf aligned/angular dim API, full-circle polar array duplicate already
covered by Sprint 1; this bundle adds save-format-from-extension,
entity_offset side selection, ARC length, properties parity (bounding_box /
rotation / char_height), mtext rotation.
COM robustness (mocked-COM tested):
- CoUninitialize on teardown; transaction commit/rollback try/finally + UNDO via
the CMDACTIVE guard; system_run_lisp guard + USERS1 value capture;
set_variable type coercion; HWND via Application.HWND; BlockInfo.description.
Security:
- HTTP remote-bind guard fires on every launch path (incl. `fastmcp run`);
StaticTokenVerifier wired into FastMCP; AutoLISP allowlist bypass-vector tests.
Hygiene: linetype-on-demand in _apply_attrs, honest view_zoom returns, snap-on-arc
sweep handling, point_tangent acos clamp, dynamic tool_groups / tool count,
word-boundary SPUR/HELICAL, undo-stack locking.
Deferred: R22 (undo/transaction stack isolation) lands with the I1 refiner (1.2),
which depends on it.
Three production-blocking defects + two legal/infra gaps from the recon pass.
R1 (CRITICAL): the 8 premium meta-tools (drawing_plan, drawing_critique,
point_from_snap, construction_xline, construction_clear, drawing_apply_iso_layers,
dimension_auto, entity_select_smart) raised NotImplementedError on the COM
backend — i.e. the entire "non-negotiable" premium workflow crashed on the
DEFAULT Windows backend. Lifted all eight to AutoCADBackend as concrete,
backend-agnostic implementations built on the shared abstract primitives +
the identical EntityInfo.properties contract, so both backends inherit them.
The only backend-specific piece left is the new `_create_xline` primitive
(XLINE has no cross-backend entity_create_* equivalent). Removes ~285 lines of
ezdxf-only duplication; the existing meta-tool test suite now covers shared code.
R2 (CRITICAL): layer_create/layer_modify/entity_set_properties used
int(lineweight), truncating every millimetre lineweight (0.50, 0.25, 0.18, 0.13)
to 0 — silently wiping the whole ISO 128 discipline, because engineering/layers.py
passes mm-floats while the MCP boundary passes hundredths-ints. Added
normalize_lineweight() to reconcile both conventions to ezdxf/COM hundredths and
wired it into all six call sites.
R3 (HIGH): _check_iso128 was a permanent no-op (everything was 0 from R2, so the
`lw <= 0: continue` guard skipped all layers). Fixed by R2; additionally exclude
CONSTRUCTION-class layers (intentionally sub-ISO 0.05mm scratch weight) to avoid
a new false positive, and corrected the misleading "normalises to mm" comment.
Also: add MIT LICENSE (referenced by CLAUDE.md but missing — legal gap) and
restore .github/workflows/ci.yml (lint kept non-blocking until the repo-wide
ruff cleanup; the test job is the real gate).
Verified: 182 passed / 2 xfailed; functional check confirms lineweights now
store as hundredths (GEOMETRY=50) and the ISO critique correctly flags a 0.40mm
layer while passing a clean ISO drawing.
Introduce the autocad-mcp-premium skill with workflow docs, examples, and references (.claude/skills/autocad-mcp-premium/*). Add PlanSpec/critique plumbing and engineering helpers (engineering/plan_spec.py, engineering/critique.py) plus tests and a smoke script. Extend backend API (backends/base.py) with corner operations and premium meta-tools (trim/extend/fillet/chamfer, drawing_plan, drawing_critique, point_from_snap, construction_xline/clear, drawing_apply_iso_layers, dimension_auto, entity_select_smart) and implement COM backend corner ops (backends/com_backend.py) with placeholders for meta-tools. Update CLAUDE.md to document the premium drawing rules and standard workflow. Misc: add examples, references, and tests for premium features, and minor server/backend adjustments.
Introduces an engineering/ package that lets MCP clients produce production-
quality technical drawings without LLM-improvised geometry. Adds 7 new MCP
tools, an 8-step pre-completion validator, and an automatic linetype + layer
bootstrap on drawing_new so CENTER/HIDDEN/PHANTOM and standard mechanical
layers (GEOMETRY, DIM, HATCH, TEXT, TITLEBLOCK, ...) are always available.
- engineering/gear.py: pure-Python involute math, 40+ points/flank, helical
+ spur front views, deterministic section A-A (no helix lines in section).
- engineering/keyway.py: DIN 6885 keyway table + parametric keyed bore /
side-section drawers.
- engineering/titleblock.py: ISO 7200 A3 (420x297 mm) title block; title
text is written verbatim to the title cell.
- engineering/validator.py: DrawingValidator with 8 checks (real DIMENSION
entities, no hidden orphans, linetypes loaded, bore + keyway in both
views when expected, title consistency e.g. forbid 'HELICAL SPUR GEAR'
when helix_angle truthy, saved-to-disk + file-on-disk, screenshot
exported, dwg path returned).
- backends/ezdxf_backend.py: AutoCAD-only linetype fallback (HIDDEN,
BORDER families) so ezdxf doc gets correct patterns when linetype_load
is called for names ezdxf.tools.standards does not ship.
- backends/base.py: concrete helpers set_layer_active / ensure_linetypes.
- server.py: Section 12 with 7 engineering tools, drawing_new(bootstrap=
True), and an ENGINEERING WORKFLOW block in the MCP instructions string.
- 30 new tests covering gear math, DIN6885 lookup, ISO A3 layout, title
verbatim, and every validator check. Tool count 89 -> 96.
