feat(reporting): add one-plate nest report PDF library slice

Add OpenNest.Reporting (net8.0, PDFsharp-MigraDoc 6.2.4) with a detached
report snapshot and a PDF writer for an empty/demand-only job or a single
plate layout: Letter portrait summary with vector part thumbnails and a
landscape plate page with a vector sheet diagram, both with Page X of Y.

- Snapshot uses reference identity for document-local R### IDs, recounts
  nested quantities from placements x copies with checked wide integers,
  excludes cutoffs from accounting, and retains no live domain objects.
- Geometry keeps Cut/Display material paths, drops rapid/scribe/lead paths,
  preserves native arcs, holes and intentional tab gaps, and rejects
  malformed programs with plate/part identification.
- Open contours and cutoffs are stroked per contour so PDFsharp cannot join
  a tab gap to the next contour.
- Bundled DejaVu Sans via a custom resolver (including MigraDoc's error
  font); unsupported text fails with the field and code point.
- Layouts beyond this slice (multiple plates, page overflow, labels that
  do not fit) fail with NotSupportedException before the destination is
  replaced; output is rendered to a temporary sibling and moved atomically.

docs/nest-reports.md

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+# Nest report PDF library
+
+The first delivery is a bounded, cross-platform library slice, not yet a desktop
+menu command or a general report layout engine. Capture a stable `Nest` on its
+owning thread, then render only the detached snapshot:
+
+```csharp
+var snapshot = NestReportBuilder.Capture(nest, DateTimeOffset.Now);
+NestPdfWriter.Write(snapshot, destinationPath);
+```
+
+Reporting does not select a post, generate CNC, refresh drawing quantities, change
+the selected plate, or certify that a layout passed geometry/pre-post checks.
+
+## Snapshot contract
+
+- IDs (`R001`, ...) are local to the report. Visit non-cutoff placements in plate
+  and part order, then append unseen demanded drawings ordered by ordinal name and
+  source path. Identity is by reference: distinct same-named drawings stay distinct,
+  including placed drawings absent from the name-keyed drawing collection.
+- Recount nested quantities from placements times sheet copies exactly once using
+  checked wide integers. Include unplaced demand; report shortage and extra
+  separately. Cached `Quantity.Nested` is not authoritative.
+- Distinguish distinct layouts from physical sheets. Per-sheet quantities do not
+  include copies; total quantities do. Utilization uses net part area divided by
+  full sheet area, excluding cutoffs.
+- Actual placed programs already contain rotations. Capture their material paths
+  with the location applied once. Preserve holes and intentional tab gaps; exclude
+  rapid, scribe, lead-in and lead-out paths. Keep Cut and Display contours.
+- If any material contour of a part is open, show all its contours without fill.
+  Do not close the gap or substitute the drawing's nominal outline. Cutoffs are
+  separate strokes with no product ID or quantity.
+- Snapshots retain values, not live drawings, parts, CNC programs or mutable
+  geometry. Invalid/missing/nonfinite geometry fails with drawing/plate context.
+
+## Initial layout and safety limits
+
+Slice 1 supports an empty/demand-only job or one plate layout: a Letter portrait
+summary page and a Letter landscape plate page, each with "Page X of Y". The
+writer rejects, with `NotSupportedException` and before touching the destination:
+
+- more than one distinct plate layout;
+- a summary (job fields, plate list, part rows with thumbnails) longer than one page;
+- a plate page (header, diagram, part table) longer than one page;
+- a part ID label that does not fit inside its part's fitted bounds at 7 pt, or
+  that overlaps another label.
+
+It never shrinks text, truncates rows or drops labels to make a layout fit.
+Multi-plate pagination, dense-label callouts and the desktop command belong to
+subsequent slices. Labels are centered on the part's bounds, which can place them
+inside a central hole; smarter placement is part of the dense-label work.
+
+Summary thumbnails and the sheet diagram are vector paths, never raster images.
+Each thumbnail is a small PDFsharp page embedded by MigraDoc as a form XObject.
+The diagram is drawn into a fixed-height table row reserved in MigraDoc's flow,
+located after layout with `DocumentRenderer.GetRenderInfoFromPage`. Closed parts
+use one even-odd filled path, so holes stay unfilled. Parts with any open contour,
+and cutoffs (dashed), stroke each contour as its own path: PDFsharp's
+`StartFigure` does not start a new subpath after an open figure, and would
+otherwise draw a false segment across a tab gap.
+
+A report is fully rendered to a unique temporary sibling before replacement of
+its destination. A failed render or write leaves an existing report untouched and
+removes temporary output. Applications should obtain overwrite consent before
+calling the library.
+
+Advanced timing, cutting distances, pierce counts, weights, costs, gas use, and
+machine/NC identity are intentionally omitted until their semantics are verified.
+The PDF can be opened or printed through a normal PDF viewer; its fitted diagram
+is not a dimensioned cutting drawing.
+
+## Backend, fonts and redistribution
+
+- Official `PDFsharp-MigraDoc` Core **6.2.4**, with `PDFsharp` **6.2.4**, targeting
+  net8.0. No GDI/WPF dependency or printer driver is used. MigraDoc owns flowing
+  document layout; PDFsharp draws vectors into its measured reserved areas.
+- DejaVu Sans **2.37**, regular and bold, is bundled unmodified as assembly
+  resources. Source: https://dejavu-fonts.github.io/ ; binary provenance:
+  Ubuntu `fonts-dejavu-core` **2.37-8**. Both required faces are embedded in PDFs;
+  neither generation nor viewing needs a platform font installation.
+- A custom resolver is installed once before fonts are created. Repeated exports
+  reuse it. An already-installed foreign resolver is an explicit integration
+  error, never silently replaced. A host that already uses PDFsharp needs resolver
+  composition before adding report support. MigraDoc's predefined error font is
+  pointed at the bundled family; its default (`Courier New`) is a platform font
+  the bundled resolver deliberately cannot supply.
+- The initial text contract is printable ASCII/Latin-1 and line/tab separators.
+  Other codepoints, controls and soft hyphens fail with the field and codepoint;
+  there is no silent missing-glyph substitution. Broader Unicode/shaping support
+  is deferred rather than implied by the font's larger character inventory.
+- PDFsharp/MigraDoc are MIT-licensed. The actual v6.2.4 license and the Microsoft
+  transitive dependency notices are in `OpenNest.Reporting/THIRD-PARTY-NOTICES.txt`.
+  Font permission/redistribution terms are in `OpenNest.Reporting/Fonts/LICENSE.txt`
+  (Bitstream Vera permission with DejaVu changes in the public domain). Preserve
+  both files in `ReportingNotices/` when publishing; embedded fonts do not replace
+  the obligation to ship their notices. Package notices are deduplicated, not
+  rewritten or shortened.
+
+## Verification
+
+```sh
+dotnet test OpenNest.Tests/OpenNest.Tests.csproj --filter FullyQualifiedName~Reporting
+```
+
+The writer tests read page sizes and content streams with PDFsharp. Text
+assertions extract with Poppler's `pdftotext -layout` and are skipped, not
+passed, when poppler-utils is absent. For manual inspection also use `pdfinfo`,
+`pdffonts` and `pdftoppm -png` (Linux verification baseline: poppler-utils
+24.02.0). Confirm page sizes, quantity rows, page X of Y, embedded fonts, native
+vector curves, unfilled holes and visible tab gaps with no connecting stroke.
+Pixel inspection supplements geometry assertions; it is not a CNC-validation
+result.
+
+Windows compilation is not runtime acceptance. The later desktop adapter must be
+tested on Windows for busy-operation guards, cancellation, overwrite handling,
+unchanged job state and PDF viewing/printing, including the packaged application.