Tag ambient audio chunks with current OpenWeather conditions

Adds weather-tag.sh, a small failure-safe helper that queries OpenWeather's
free "Current weather" endpoint and prints one tag from a fixed vocabulary
(thunderstorm, rain, rainshower, snow, snowstorm, fog, windy, cloudy, clear)
or nothing on any failure.

ambient-record.sh calls it just before each 30-minute chunk so the filename
reflects conditions at the moment of capture, e.g.
  east-08-30-00-thunderstorm.m4a
  east-12-00-00-clear.m4a
A foggy dawn no longer mislabels the sunny afternoon files.

Off by default. Enable with WEATHER_ENABLED=true and an
OPENWEATHER_API_KEY entry in .env; missing key / API error / disabled
toggle all fall through to the un-tagged filename, never blocking the
recorder.

ambient-record.sh

@@ -50,7 +50,17 @@ while true; do
     mkdir -p "$dir"
 
     timestamp=$(date +%H-%M-%S)
-    outfile="$dir/${CAM}-${timestamp}.m4a"
+
+    # Weather tag for THIS chunk — queried right before recording so the
+    # filename reflects conditions at the time of capture, not earlier in the
+    # day.  weather-tag.sh prints empty on disabled / missing key / API error,
+    # so the un-tagged filename is the safe fallback.
+    weather_tag=$("$SCRIPT_DIR/weather-tag.sh" 2>/dev/null || true)
+    if [ -n "$weather_tag" ]; then
+        outfile="$dir/${CAM}-${timestamp}-${weather_tag}.m4a"
+    else
+        outfile="$dir/${CAM}-${timestamp}.m4a"
+    fi
 
     echo "[$(date '+%Y-%m-%d %H:%M:%S')] Recording → $outfile  (${CHUNK}s)"