Registra spento sul frame gia' registrato, nuovo grab dopo il reset

Refs #123

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/frontend/flask_app/static/js/vision_execute.js

@@ -32,6 +32,7 @@ function visionExecute() {
     preview: false,    // result on screen is an analysis only, not saved
     saved: false,      // «Registra» done: the saved result replaces the preview
     lastBlob: null,    // last frame shown, the one «Registra» saves
+    recordedBlob: null, // #123: frame saved by the last successful «Registra»: not recordable twice
     paused: false,     // operator paused the in-line loop
     registering: false, // «Registra» in progress: the loop stands still
     leaving: false,    // page is being left: no more requests
@@ -43,8 +44,10 @@ function visionExecute() {
       // #120: «Rimisura»/nuovo ciclo (task-result-reset): il pezzo va registrato di nuovo, anche senza camera
       window.addEventListener('task-result-reset', () => {
         this.saved = false;
-        this.preview = !!this.result;
-        this.kick();
+        // #123: il frame gia' registrato non e' piu' un'anteprima ne' si registra due volte
+        this.preview = !!this.result && this.lastBlob !== this.recordedBlob;
+        // #123: camera impulsiva = frame nuovo subito (come all'apertura); in linea riparte il ciclo
+        if (this.hasCamera && !this.inLinea) this.grab(); else this.kick();
       });
       if (!this.hasCamera) return;
       document.addEventListener('visibilitychange', () => { if (!document.hidden) this.kick(); });
@@ -58,7 +61,7 @@ function visionExecute() {
     get hasCamera() { return !!(window.__visionCfg || {}).cameraAvailable; },
     get inLinea() { return this.hasCamera && (window.__visionCfg || {}).modo === 'in_linea'; },
     // «Registra» needs a frame on screen that is not saved yet
-    get canRecord() { return !!this.lastBlob && !this.saved && !this.registering; },
+    get canRecord() { return !!this.lastBlob && this.lastBlob !== this.recordedBlob && !this.saved && !this.registering; },  // #123: non sul frame gia' registrato
 
     shouldRun() {
       return this.inLinea && !this.paused && !this.saved && !this.registering
@@ -145,6 +148,7 @@ function visionExecute() {
         if (!this.error && this.result && this.result.vision_result_id) {
           this.preview = false;
           this.saved = true;
+          this.recordedBlob = blob;   // #123: questo frame e' registrato, Registra resta spento finche' non ne arriva uno nuovo
           this._emitRecorded();   // #120: la pagina conta le quote registrate
         }
       } finally {