fix: Handle HALO remarks and ignore '/' separator in METAR

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

metar.html

@@ -262,7 +262,8 @@
             const specialRemarks = {
                 'FROIN': 'Frontal passage in vicinity',
                 'CONTRAILS': 'Contrails observed',
-                'VIRGA': 'Virga (precipitation not reaching the ground)'
+                'VIRGA': 'Virga (precipitation not reaching the ground)',
+                'HALO': 'Halo phenomenon observed'
             };
             const directions = {
                 'N': 'North', 'NE': 'Northeast', 'E': 'East', 'SE': 'Southeast',
@@ -335,6 +336,8 @@
                     decoded.push(`  - ${decodeWeather(part, metarString)}`);
                 } else if (part.match(/^(AC|CI|CC)/)) {
                      decoded.push(`  - ${part}: Cloud types and coverage details`);
+                } else if (part === '/') {
+                    // separator, ignore
                 } else {
                      console.log(`Other remark: ${part} in METAR: ${metarString}`);
                      decoded.push(`  - ${part}: Other remark`);