Fix number field validation: strip text from numeric answers

Number inputs (type="number") were getting answers like "5 years"
instead of "5", causing LinkedIn validation errors. Now:
- AI gets "(must be a number, no text or units)" hint
- Answers are stripped to digits before filling

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

lib/form_filler.mjs

@@ -568,12 +568,18 @@ Answer:`;
         continue;
       }
 
-      const formatHint = field.placeholder ? `(format: ${field.placeholder})` : '';
+      let formatHint = field.placeholder ? `(format: ${field.placeholder})` : '';
+      if (field.type === 'number') formatHint = '(must be a number, no text or units)';
       let answer = this.answerFor(lbl);
       if (!answer && field.required) {
         answer = await this.aiAnswerFor(formatHint ? `${lbl} ${formatHint}` : lbl);
         if (answer) this.saveAnswer(lbl, answer);
       }
+      // For number fields, extract just the numeric value
+      if (answer && field.type === 'number') {
+        const num = String(answer).replace(/[^\d.]/g, '');
+        if (num) answer = num;
+      }
       if (answer && answer !== this.profile.cover_letter) {
         const el = await byTag(field.tag);
         if (!el) continue;