Draw estimate signatures as vector TikZ instead of PNG

The estimate foot now renders the provider and client signatures as
TikZ \draw/\fill paths straight from the captured stroke data, in two
side-by-side minipages with a \useasboundingbox so the boxes align
regardless of stroke coverage. A side that hasn't signed shows a
signature rule.

- TeXHelpers.SignatureToTikz walks the PostIt wire format
  ([k, x0,y0, ...] per stroke, coords in [0, CoordinateMax], y-down)
  and emits one \draw per stroke (round caps/joins, 1.5pt), flipping y
  so the signature is upright on paper; a single-point tap becomes a
  filled dot, mirroring the Avalonia round-capped Polyline.
- FrontOfficeApiController.LoadEstimateForRenderAsync includes
  Estimate.Signatures so SignaturePro/SignatureClient resolve.
- Estimate_tex.cshtml drops the \includegraphics of a PNG (which
  failed the build when the file was absent) and adds \usepackage{tikz}.
- README: document texlive-pictures (tikz) and texlive-fonts-extra
  (bera) as runtime deps; bera.sty missing is the likely cause of the
  remaining host Emergency stop.

Co-Authored-By: Claude Code <noreply@anthropic.com>

README.md

@@ -73,7 +73,7 @@ systemd `yavscApi`.
 Sous Debian/Ubuntu :
 
 ```bash
-sudo apt install texlive-binaries texlive-luatex
+sudo apt install texlive-binaries texlive-luatex texlive-pictures texlive-fonts-extra
 ```
 
 - `texlive-binaries` fournit l'exécutable `lualatex` (collection basic).
@@ -82,6 +82,11 @@ sudo apt install texlive-binaries texlive-luatex
   `module 'luaotfload-main' not found … Emergency stop` et ne produit aucun PDF.
   (Sur les Debian récents, `luaotfload` a migré de `texlive-latex-extra` vers
   `texlive-luatex` — avoir `texlive-latex-extra` seul ne suffit plus.)
+- `texlive-pictures` fournit `tikz`/`pgf`, utilisé pour dessiner les signatures
+  du client et du fournisseur en bas du devis (vecteur, pas de PNG).
+- `texlive-fonts-extra` fournit la fonte `bera` chargée par le modèle de devis.
+  Sans elle, lualatex s'arrête sur `! LaTeX Error: File 'bera.sty' not found`
+  (`Emergency stop`, aucun PDF).
 
 Sur un hôte sans `lualatex`, les endpoints PDF renvoient une erreur 500 « PDF
 generation failed » ; l'endpoint TeX (`estimate.tex`) reste utilisable et permet

src/Yavsc.Api/Controllers/Business/FrontOfficeApiController.cs

@@ -157,12 +157,14 @@ namespace Yavsc.ApiControllers
       }
 
         // Loads the estimate linked to a query with the navigation the
-        // Estimate_tex template reads (client + performer profile + bill).
+        // Estimate_tex template reads (client + performer profile + bill
+        // + the captured signatures, drawn as tikz at the foot of the devis).
         private Task<Estimate?> LoadEstimateForRenderAsync(long queryId, CancellationToken token)
             => dbContext.Estimates
                 .Where(e => e.CommandId == queryId)
                 .OrderByDescending(e => e.Id)
                 .Include(e => e.Bill)
+                .Include(e => e.Signatures)
                 .Include(e => e.Query).ThenInclude(q => q!.Client).ThenInclude(c => c!.PostalAddress)
                 .Include(e => e.Query).ThenInclude(q => q!.PerformerProfile).ThenInclude(p => p!.OrganizationAddress)
                 .Include(e => e.Query).ThenInclude(q => q!.PerformerProfile).ThenInclude(p => p!.Performer)

src/Yavsc.Api/Helpers/TeXHelpers.cs

@@ -1,9 +1,12 @@
 using System.Diagnostics;
+using System.Globalization;
+using System.Text;
 using Microsoft.AspNetCore.Html;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.ViewEngines;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Yavsc.Models.Billing;
 
 namespace Yavsc.Helpers
 {
@@ -116,6 +119,69 @@ namespace Yavsc.Helpers
             return new TeXString(string.Join(lineSeparator,texlines));
         }
 
+        /// <summary>
+        /// Renders a captured signature as TikZ <c>\draw</c>/<c>\fill</c>
+        /// paths, suitable for embedding in a <c>tikzpicture</c> at the
+        /// foot of a devis. The signature is the PostIt wire format — a
+        /// length-prefixed sequence of strokes, each stroke being
+        /// <c>[k, x0, y0, x1, y1, …]</c> with coordinates normalised to
+        /// <c>[0, CoordinateMax]</c> and y growing downward (screen
+        /// orientation). We denormalise to a <paramref name="widthCm"/> ×
+        /// <paramref name="heightCm"/> canvas and flip y so the signature
+        /// appears upright on paper. A single-point stroke (a pen-down
+        /// tap) is rendered as a filled dot, mirroring the round-capped
+        /// <c>Polyline</c> the Avalonia pad draws for it.
+        /// </summary>
+        /// <param name="sig">The persisted signature. Null/empty yields
+        /// <see cref="HtmlString.Empty"/>, so the caller can gate the
+        /// <c>tikzpicture</c> on a non-empty result.</param>
+        public static HtmlString SignatureToTikz(
+            this Signature sig, double widthCm, double heightCm)
+        {
+            if (sig is null || sig.Strokes is null || sig.Strokes.Length == 0)
+                return HtmlString.Empty;
+
+            double max = sig.CoordinateMax > 0 ? sig.CoordinateMax : 10_000.0;
+            var strokes = sig.Strokes;
+            var sb = new StringBuilder();
+
+            int i = 0;
+            while (i < strokes.Length)
+            {
+                int k = strokes[i];
+                if (k <= 0) break;
+                if (i + 1 + 2 * k > strokes.Length) break;
+                i++; // skip the length prefix
+
+                // A single-point stroke: a tap. Draw a round dot so it
+                // shows instead of a zero-length, invisible \draw.
+                if (k == 1)
+                {
+                    double px = strokes[i] / max * widthCm;
+                    double py = heightCm - strokes[i + 1] / max * heightCm;
+                    sb.Append(CultureInfo.InvariantCulture,
+                        $"\\fill ({px:F3},{py:F3}) circle (0.8pt); ");
+                    i += 2;
+                    continue;
+                }
+
+                sb.Append("\\draw[line cap=round, line join=round, line width=1.5pt] ");
+                for (int p = 0; p < k; p++)
+                {
+                    double px = strokes[i + 2 * p] / max * widthCm;
+                    double py = heightCm - strokes[i + 2 * p + 1] / max * heightCm;
+                    if (p == 0) sb.Append(CultureInfo.InvariantCulture,
+                        $"({px:F3},{py:F3})");
+                    else sb.Append(CultureInfo.InvariantCulture,
+                        $" -- ({px:F3},{py:F3})");
+                }
+                sb.Append("; ");
+                i += 2 * k;
+            }
+
+            return new HtmlString(sb.ToString());
+        }
+
         public static FileInfo GenerateEstimatePdf(this PdfGenerationViewModel Model)
         {
             string errorMsg = null;

src/Yavsc.Api/Views/Shared/Estimate_tex.cshtml

@@ -11,7 +11,6 @@
     var proaddr = Model.Query.PerformerProfile.OrganizationAddress.Address.SplitAddressToTeX();
     var proaddrm = new HtmlString(Model.Query.PerformerProfile.OrganizationAddress.Address);
     var isestimate = !ViewBag.AsBill;
-    var prosign = new FileInfo($"{ViewBag.BillsDir}/estimate-prosign-{Model.Id}.png");
 
 }
 \documentclass[french,11pt]{article}
@@ -25,6 +24,7 @@
 \usepackage{graphicx}
 \usepackage{fancyhdr}
 \usepackage{fp}
+\usepackage{tikz}
 
 \def\TVA{20}    % Taux de la TVA
 
@@ -188,19 +188,46 @@
 }
 
 
-@if (!(Model.ProviderValidationDate==null)) {
+@{
-    <text>
+    // Captured signatures, if any. The Estimate.Signatures collection
-\begin{flushright}
+    // is loaded by the controller; SignaturePro/SignatureClient project
-  @(new HtmlString(isestimate?"Devis validé":"Facture validée")) le @TeXHelpers.ToTeX(Model.ProviderValidationDate.ToString("dddd dd MMMM yyyy"))
+    // the row by type. We draw them as vector TikZ at the foot of the
-\end{flushright}
+    // devis (see TeXHelpers.SignatureToTikz), so there is no PNG to
-@if (prosign.Exists) {
+    // produce or \includegraphics to fail on.
-<text>
+    var fr = CultureInfo.CreateSpecificCulture("fr-FR");
-\begin{center}
+    var proSig = Model.SignaturePro;
-	\hspace{263pt}
+    var cliSig = Model.SignatureClient;
-    \includegraphics[height=60pt]{@(ViewBag.BillsDir)/estimate-prosign-@(Model.Id).png}
-\end{center}
-</text>
 }
-    </text>
+
+\vspace{2em}
+\noindent
+\begin{minipage}[t]{0.45\textwidth}
+  \textbf{Signature du fournisseur}\\
+@if (Model.ProviderValidationDate != default(DateTime)) {
+<text>\small Validé le @TeXHelpers.ToTeX(Model.ProviderValidationDate.ToString("dddd dd MMMM yyyy", fr))\\</text>
 }
+@if (proSig != null && proSig.Strokes != null && proSig.Strokes.Length > 0) {
+<text>\begin{tikzpicture}
+  \useasboundingbox (0,0) rectangle (5,2.5);
+  @proSig.SignatureToTikz(5, 2.5)
+\end{tikzpicture}</text>
+} else {
+<text>\rule[-2.2cm]{5cm}{0.4pt}</text>
+}
+\end{minipage}\hfill
+\begin{minipage}[t]{0.45\textwidth}
+  \textbf{Signature du client}\\
+@if (Model.ClientValidationDate != default(DateTime)) {
+<text>\small Validé le @TeXHelpers.ToTeX(Model.ClientValidationDate.ToString("dddd dd MMMM yyyy", fr))\\</text>
+}
+@if (cliSig != null && cliSig.Strokes != null && cliSig.Strokes.Length > 0) {
+<text>\begin{tikzpicture}
+  \useasboundingbox (0,0) rectangle (5,2.5);
+  @cliSig.SignatureToTikz(5, 2.5)
+\end{tikzpicture}</text>
+} else {
+<text>\rule[-2.2cm]{5cm}{0.4pt}</text>
+}
+\end{minipage}
+
 \end{document}