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.

sky-cam.conf

@@ -174,6 +174,38 @@ LATITUDE="${LATITUDE:-0.0000}"
 LONGITUDE="${LONGITUDE:-0.0000}"
 TIMEZONE="${TIMEZONE:-America/New_York}"
 
+# ── Weather tagging (OpenWeather) ─────────────────────────────────────────────
+# When enabled, ambient-record.sh queries OpenWeather's "Current weather"
+# endpoint just before each 30-minute audio chunk and appends a one-word
+# weather tag to the filename, e.g.:
+#     east-08-30-00-thunderstorm.m4a
+#     east-09-00-00-rain.m4a
+#     east-09-30-00-cloudy.m4a
+# That way each chunk is labelled with what was happening DURING that chunk —
+# a foggy dawn won't mislabel the sunny afternoon files.
+#
+# Tag vocabulary (fixed set — anything else → no tag):
+#     thunderstorm  rain  rainshower  snow  snowstorm
+#     fog  windy  cloudy  clear
+#
+# Setup:
+#   1. Get a free API key: https://openweathermap.org/api
+#      (the free "Current weather" tier — 60 calls/min — is plenty)
+#   2. Add to .env:   OPENWEATHER_API_KEY=xxxxxxxxxxxxxxxxxxxxxxxx
+#   3. Confirm LATITUDE / LONGITUDE are set in .env (already needed by sunrise.py)
+#   4. Flip WEATHER_ENABLED=true below
+#
+# The query uses the same LATITUDE / LONGITUDE configured above — one location
+# for the whole installation; per-camera coordinates are not supported.
+#
+# Failure-safe: if the toggle is off, the key is missing, the network is down,
+# or the API errors out, weather-tag.sh prints nothing and the recorder falls
+# back to the un-tagged filename.  ambient-record.sh never blocks on this.
+#
+# Manual test:   ./weather-tag.sh        (prints e.g. "cloudy" or nothing)
+WEATHER_ENABLED=false
+OPENWEATHER_API_KEY="${OPENWEATHER_API_KEY:-}"
+
 # ── Cameras ───────────────────────────────────────────────────────────────────
 # List every camera name here (space-separated inside the parentheses).
 # Each name becomes a subfolder under BASE_DIR (images) and BASE_DIR/movies.