release: v1.5.0 — discovery layer, honesty debt closed, Wave A

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>

engineering/titleblock.py

@@ -59,11 +59,50 @@ async def apply_iso_a3_titleblock(
     *,
     metadata: TitleBlockMetadata,
     origin: tuple[float, float] = (0.0, 0.0),
+    layout: str | None = None,
 ) -> dict:
-    """Draw a 420x297 ISO 7200 title block at `origin` (lower-left of sheet)."""
+    """Draw a 420x297 ISO 7200 title block at `origin` (lower-left of sheet).
+
+    With `layout`, the sheet is drawn on that paper-space layout — which is
+    where a title block belongs, since the border frames the printed sheet
+    rather than the model. The caller's current space is restored afterwards, so
+    asking for a sheet border does not silently move them onto the sheet.
+    Without `layout` it draws in whatever space is current, as it always did.
+    """
 
     ox, oy = float(origin[0]), float(origin[1])
 
+    previous_space = "Model"
+    if layout is not None:
+        listing = await backend.layout_list()
+        names = {str(entry) for entry in (listing.get("layouts") or [])}
+        if layout not in names:
+            raise RuntimeError(
+                f"apply_iso_a3_titleblock: layout {layout!r} does not exist "
+                f"(have: {', '.join(sorted(str(n) for n in names))}). Create it with "
+                "layout_create first."
+            )
+        previous_space = getattr(backend, "_current_space", "Model")
+        switched = await backend.layout_set_current(layout)
+        if not switched.get("ok", True):
+            raise RuntimeError(f"apply_iso_a3_titleblock: {switched.get('error')}")
+
+    try:
+        return await _draw_titleblock(backend, metadata=metadata, ox=ox, oy=oy, layout=layout)
+    finally:
+        if layout is not None:
+            await backend.layout_set_current(previous_space)
+
+
+async def _draw_titleblock(
+    backend: AutoCADBackend,
+    *,
+    metadata: TitleBlockMetadata,
+    ox: float,
+    oy: float,
+    layout: str | None,
+) -> dict:
+
     # ---- outer + inner borders -------------------------------------------------
     outer_pts = [
         [ox, oy],
@@ -263,6 +302,8 @@ async def apply_iso_a3_titleblock(
     )
 
     return {
+        "ok": True,
+        "layout": layout or "Model",
         "outer_border": outer.handle,
         "inner_border": inner.handle,
         "titleblock_lines": titleblock_lines,