feat: FASE 5b/6.1+6.2 - SPC Backend + Dashboard Metrologist (Plotly.js)

Aggiunge servizio SPC con calcoli Cp/Cpk/Pp/Ppk, carta di controllo (UCL/LCL),
istogramma con curva normale. Router FastAPI con 5 endpoint statistics, blueprint
Flask con proxy AJAX, dashboard interattiva Alpine.js + Plotly.js con filtri per
ricetta/subtask/date, riepilogo pass/fail, gauge Cpk e i18n IT/EN completo.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/templates/measure/task_execute.html

@@ -55,9 +55,8 @@
 <div class="min-h-[calc(100vh-3.5rem)] flex flex-col"
      x-data="taskExecute()"
      x-init="init()"
-     @numpad-confirm.window="handleMeasurement($event.detail.value)"
-     @marker-click.window="goToSubtaskByMarker($event.detail.marker_number)"
-     @caliper-reading.window="handleCaliperReading($event.detail.value)">
+     @numpad-confirm.window="handleMeasurement($event.detail.value, $event.detail.inputMethod)"
+     @marker-click.window="goToSubtaskByMarker($event.detail.marker_number)">
 
   {# ================================================================
      HEADER — Task info + traceability
@@ -628,7 +627,7 @@ function taskExecute() {
     },
 
     // ---- Handle numpad confirm ----
-    async handleMeasurement(value) {
+    async handleMeasurement(value, inputMethod) {
       if (!this.currentSubtask || this.saving) return;
 
       this.currentValue = value;
@@ -657,6 +656,7 @@ function taskExecute() {
             deviation: dev,
             lot_number: this.lotNumber,
             serial_number: this.serialNumber,
+            input_method: inputMethod || 'manual',
           }),
         });
 
@@ -732,12 +732,6 @@ function taskExecute() {
       }
     },
 
-    // ---- Caliper reading ----
-    handleCaliperReading(value) {
-      // Auto-fill value from USB caliper
-      this.currentValue = value;
-    },
-
     // ---- Go to summary ----
     goToSummary() {
       const recipeId = this.task.version_id || this.task.recipe_id || 0;