diff --git a/4-seasons.sh b/4-seasons.sh
index dea6060..54a903e 100755
--- a/4-seasons.sh
+++ b/4-seasons.sh
@@ -11,10 +11,11 @@ set -euo pipefail
 set -x
 
 SCRIPT_DIR="$(dirname "$(realpath "$0")")"
+source "$SCRIPT_DIR/sky-cam.conf"
 
 # ── Configuration ──────────────────────────────────────────────────────────────
-base_dir="/home/motion/drives/local-2tb"
-music_base_dir="$base_dir/music/4 Seasons"
+base_dir="$BASE_DIR"
+music_base_dir="$MUSIC_DIR"
 [ ! -d "$music_base_dir" ] && music_base_dir="$SCRIPT_DIR/music"
 
 # ── Date setup ────────────────────────────────────────────────────────────────
@@ -23,8 +24,9 @@ echo "Processing: $yesterday"
 
 # ── Season / movement info from astronomical calculation ──────────────────────
 eval "$(python3 "$SCRIPT_DIR/season_info.py" "$yesterday")"
-# Provides: SEASON  MVT_NUM  DAY_OF_MVT  DAYS_IN_MVT  MVT_START  MVT_END  IS_LAST_DAY
-echo "Season=$SEASON  Mvt=$MVT_NUM  Day=$DAY_OF_MVT/$DAYS_IN_MVT  LastDay=$IS_LAST_DAY"
+# Provides: SEASON  MVT_NUM  DAY_OF_MVT  DAYS_IN_MVT  MVT_START  MVT_END
+#           IS_LAST_DAY  ASTRO_YEAR
+echo "Season=$SEASON  Mvt=$MVT_NUM  Year=$ASTRO_YEAR  Day=$DAY_OF_MVT/$DAYS_IN_MVT  LastDay=$IS_LAST_DAY"
 
 # ── Locate music file and get its duration ────────────────────────────────────
 music_file=$(find "$music_base_dir" -type f -iname "*${SEASON}*Mvt*${MVT_NUM}*" | sort | head -n 1)
@@ -57,7 +59,7 @@ fi
 echo "Images found: $total_images"
 
 # ── Prepare output directory ──────────────────────────────────────────────────
-output_dir="$base_dir/movies/$script_name/$SEASON/Mvt$MVT_NUM"
+output_dir="$base_dir/movies/$script_name/$ASTRO_YEAR/$SEASON/Mvt$MVT_NUM"
 mkdir -p "$output_dir"
 
 # ── Build sorted image list ───────────────────────────────────────────────────
diff --git a/fullday-video.sh b/fullday-video.sh
index 955f29f..be9fcf2 100755
--- a/fullday-video.sh
+++ b/fullday-video.sh
@@ -8,9 +8,10 @@
 set -euo pipefail
 
 SCRIPT_DIR="$(dirname "$(realpath "$0")")"
+source "$SCRIPT_DIR/sky-cam.conf"
 
 # ── Configuration ──────────────────────────────────────────────────────────────
-base_dir="/home/motion/drives/local-2tb"
+base_dir="$BASE_DIR"
 FULLDAY_FPS=5       # timelapse frame rate — adjust to taste
 RETENTION_DAYS=10   # full-day videos older than this are deleted
 
diff --git a/images/stitch-preview/cyl-f1550-preview.jpg b/images/stitch-preview/cyl-f1550-preview.jpg
new file mode 100644
index 0000000..637be37
Binary files /dev/null and b/images/stitch-preview/cyl-f1550-preview.jpg differ
diff --git a/images/stitch-preview/cyl-f1920-preview.jpg b/images/stitch-preview/cyl-f1920-preview.jpg
new file mode 100644
index 0000000..9c80fba
Binary files /dev/null and b/images/stitch-preview/cyl-f1920-preview.jpg differ
diff --git a/montage-mvt.sh b/montage-mvt.sh
index ebff07c..8ae114e 100755
--- a/montage-mvt.sh
+++ b/montage-mvt.sh
@@ -1,52 +1,57 @@
 #!/bin/bash
-# montage-mvt.sh — compile all daily clips for the current Vivaldi movement into
-# a single montage that exactly matches the music duration, with 2-second
-# audio/video fade in/out and a 7-second attribution card appended.
+# montage-mvt.sh — compile one Vivaldi movement's daily clips into a montage.
+#
+# Duration matches the movement's music exactly.  Attribution is overlaid as a
+# translucent bar across the top of the video for the first ATTR_DUR seconds
+# (fade in/out) — no separate card appended, so year-end joining is a plain
+# concat with no duplicate attribution concerns.
 #
 # Called automatically by 4-seasons.sh on the last day of each movement.
-# Can also be run manually (e.g. to build a partial mid-season preview).
+# Can also be run manually for a mid-season preview.
+#
+# On the last day of Autumn Mvt 3, automatically triggers year-end-join.sh.
 #
 # Music: "The Four Seasons" by Antonio Vivaldi
 # Performed by John Harrison with the Wichita State University Chamber Players
 # Source: Free Music Archive — freemusicarchive.org
-# License: CC BY-SA 3.0 — creativecommons.org/licenses/by-sa/3.0
+# License: CC BY-SA 3.0
 
 set -euo pipefail
 
 SCRIPT_DIR="$(dirname "$(realpath "$0")")"
+source "$SCRIPT_DIR/sky-cam.conf"
 
 # ── Configuration ──────────────────────────────────────────────────────────────
-base_dir="/home/motion/drives/local-2tb"
-music_base_dir="$base_dir/music/4 Seasons"
+base_dir="$BASE_DIR"
+music_base_dir="$MUSIC_DIR"
 [ ! -d "$music_base_dir" ] && music_base_dir="$SCRIPT_DIR/music"
 
-FADE_DUR=2.0   # seconds for video + audio fade in/out
-ATTR_DUR=7     # duration of attribution card in seconds
+FADE_DUR=2.0   # video + audio fade in/out (seconds)
+ATTR_DUR=6     # attribution overlay duration (seconds from start)
+ATTR_FADE=1    # attribution fade in / fade out duration
 
 # ── Season / movement info ────────────────────────────────────────────────────
-# Optional first argument: YYYY-MM-DD of the last day of the movement to compile.
-# Used when called automatically from 4-seasons.sh (which processes yesterday's
-# images the next morning, so "today" would already be the next movement).
-# When run manually with no argument, uses today — correct for same-day runs.
 DATE_ARG="${1:-}"
 eval "$(python3 "$SCRIPT_DIR/season_info.py" ${DATE_ARG:+"$DATE_ARG"})"
-echo "Season=$SEASON  Mvt=$MVT_NUM  Day=$DAY_OF_MVT/$DAYS_IN_MVT  (ref date: ${DATE_ARG:-today})"
+# Provides: SEASON  MVT_NUM  DAY_OF_MVT  DAYS_IN_MVT  MVT_START  MVT_END
+#           IS_LAST_DAY  ASTRO_YEAR
+echo "Season=$SEASON  Mvt=$MVT_NUM  Year=$ASTRO_YEAR  (ref: ${DATE_ARG:-today})"
 
 # ── Locate files ──────────────────────────────────────────────────────────────
 script_name=$(basename "$SCRIPT_DIR" | cut -d'-' -f1)
-video_dir="$base_dir/movies/$script_name/$SEASON/Mvt$MVT_NUM"
+video_dir="$base_dir/movies/$script_name/$ASTRO_YEAR/$SEASON/Mvt$MVT_NUM"
 output_dir="$video_dir/montage"
 mkdir -p "$output_dir"
 
 music_file=$(find "$music_base_dir" -type f -iname "*${SEASON}*Mvt*${MVT_NUM}*" | sort | head -n 1)
 if [ -z "$music_file" ]; then
-    echo "ERROR: Music file not found for $SEASON Mvt $MVT_NUM"
+    echo "ERROR: Music file not found for $SEASON Mvt $MVT_NUM in $music_base_dir"
     exit 1
 fi
 music_duration=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$music_file")
-echo "Music: $(basename "$music_file")  ($music_duration s)"
+echo "Music: $(basename "$music_file")  (${music_duration}s)"
 
-# ── Collect sorted daily clips ─────────────────────────────────────────────────
+# ── Collect sorted daily clips ────────────────────────────────────────────────
 mapfile -d '' daily_clips < <(find "$video_dir" -maxdepth 1 -name "*-final.mp4" -print0 | sort -z)
 if [ "${#daily_clips[@]}" -eq 0 ]; then
     echo "ERROR: No *-final.mp4 clips in $video_dir"
@@ -54,65 +59,13 @@ if [ "${#daily_clips[@]}" -eq 0 ]; then
 fi
 echo "Found ${#daily_clips[@]} daily clips"
 
-# ── Detect source resolution from first clip ──────────────────────────────────
-# The attribution card is created at this same resolution so nothing is resized.
+# ── Source resolution ─────────────────────────────────────────────────────────
 VIDEO_W=$(ffprobe -v error -select_streams v:0 -show_entries stream=width  -of csv=p=0 "${daily_clips[0]}")
 VIDEO_H=$(ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=p=0 "${daily_clips[0]}")
 echo "Source resolution: ${VIDEO_W}x${VIDEO_H}"
 
-# ── Temp-file tracking ────────────────────────────────────────────────────────
-TMPFILES=()
-cleanup() { rm -f "${TMPFILES[@]}" 2>/dev/null || true; }
-trap cleanup EXIT
-
-concat_list=$(mktemp --suffix=.txt); TMPFILES+=("$concat_list")
-printf "file '%s'\n" "${daily_clips[@]}" > "$concat_list"
-
-# ── Step 1: Concatenate clips, normalising to source resolution ───────────────
-# Normalise in case any clip differs (e.g. camera settings changed on one day).
-temp_concat=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_concat")
-echo "Step 1/5: concatenating ${#daily_clips[@]} clips..."
-ffmpeg -loglevel warning \
-    -f concat -safe 0 -i "$concat_list" \
-    -vf "scale=${VIDEO_W}:${VIDEO_H}:force_original_aspect_ratio=decrease,\
-pad=${VIDEO_W}:${VIDEO_H}:(ow-iw)/2:(oh-ih)/2,setsar=1" \
-    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
-    -y "$temp_concat"
-
-# ── Step 2: Speed-adjust to match music duration exactly ──────────────────────
-concat_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$temp_concat")
-speed_factor=$(echo "scale=6; $concat_dur / $music_duration" | bc)
-echo "Step 2/5: speed factor $speed_factor  (raw=${concat_dur}s  music=${music_duration}s)"
-
-temp_sped=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_sped")
-ffmpeg -loglevel warning \
-    -i "$temp_concat" \
-    -vf "setpts=PTS/$speed_factor" \
-    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
-    -t "$music_duration" -y "$temp_sped"
-rm "$temp_concat"
-
-# ── Step 3: Merge with music + 2-second video/audio fade in/out ───────────────
-fade_out_start=$(echo "scale=3; $music_duration - $FADE_DUR" | bc)
-echo "Step 3/5: adding music and fades..."
-
-temp_main=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_main")
-ffmpeg -loglevel warning \
-    -i "$temp_sped" -i "$music_file" \
-    -filter_complex \
-"[0:v]fade=t=in:st=0:d=${FADE_DUR},fade=t=out:st=${fade_out_start}:d=${FADE_DUR}[vout];\
-[1:a]afade=t=in:st=0:d=${FADE_DUR},afade=t=out:st=${fade_out_start}:d=${FADE_DUR}[aout]" \
-    -map "[vout]" -map "[aout]" \
-    -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 192k \
-    -t "$music_duration" -y "$temp_main"
-rm "$temp_sped"
-
-# ── Step 4: Create 7-second attribution card at source resolution ─────────────
-# Resolution matches the video — no resizing of the main montage required.
-echo "Step 4/5: creating attribution card at ${VIDEO_W}x${VIDEO_H}..."
-
-FONT=""
-FONT_BOLD=""
+# ── Font detection ────────────────────────────────────────────────────────────
+FONT=""; FONT_BOLD=""
 if command -v fc-match &>/dev/null; then
     FONT=$(fc-match "DejaVu Sans:style=Regular" --format="%{file}" 2>/dev/null || true)
     FONT_BOLD=$(fc-match "DejaVu Sans:style=Bold"    --format="%{file}" 2>/dev/null || true)
@@ -128,32 +81,91 @@ if [ -z "$FONT" ]; then
 fi
 [ -z "$FONT_BOLD" ] && FONT_BOLD="$FONT"
 
-# Font sizes are proportional to frame height so they look right at any resolution.
-# Colons inside drawtext text values must be escaped as \: (\\: in bash double-quotes).
-DT="drawtext=fontfile='${FONT_BOLD}':text='The Four Seasons - Antonio Vivaldi':fontcolor=white:fontsize=h/19:x=(w-text_w)/2:y=h*0.15"
-DT="${DT},drawtext=fontfile='${FONT}':text='Performed by John Harrison':fontcolor=0xDDDDDD:fontsize=h/26:x=(w-text_w)/2:y=h*0.32"
-DT="${DT},drawtext=fontfile='${FONT}':text='with the Wichita State University Chamber Players':fontcolor=0xDDDDDD:fontsize=h/30:x=(w-text_w)/2:y=h*0.43"
-DT="${DT},drawtext=fontfile='${FONT}':text='Source\\: Free Music Archive':fontcolor=white:fontsize=h/32:x=(w-text_w)/2:y=h*0.57"
-DT="${DT},drawtext=fontfile='${FONT}':text='freemusicarchive.org':fontcolor=0xFFFF88:fontsize=h/32:x=(w-text_w)/2:y=h*0.66"
-DT="${DT},drawtext=fontfile='${FONT}':text='License\\: CC BY-SA 3.0':fontcolor=0xCCCCCC:fontsize=h/34:x=(w-text_w)/2:y=h*0.76"
-DT="${DT},fade=t=in:st=0:d=1,fade=t=out:st=$((ATTR_DUR-1)):d=1"
+# ── Temp files ────────────────────────────────────────────────────────────────
+TMPFILES=()
+cleanup() { rm -f "${TMPFILES[@]}" 2>/dev/null || true; }
+trap cleanup EXIT
 
-temp_attr=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_attr")
+concat_list=$(mktemp --suffix=.txt); TMPFILES+=("$concat_list")
+printf "file '%s'\n" "${daily_clips[@]}" > "$concat_list"
+
+# ── Step 1: Concatenate + normalise resolution ────────────────────────────────
+temp_concat=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_concat")
+echo "Step 1/3: concatenating ${#daily_clips[@]} clips..."
 ffmpeg -loglevel warning \
-    -f lavfi -i "color=c=black:s=${VIDEO_W}x${VIDEO_H}:r=25:d=${ATTR_DUR}" \
-    -f lavfi -i "anullsrc=r=44100:cl=stereo" \
-    -vf "$DT" \
+    -f concat -safe 0 -i "$concat_list" \
+    -vf "scale=${VIDEO_W}:${VIDEO_H}:force_original_aspect_ratio=decrease,\
+pad=${VIDEO_W}:${VIDEO_H}:(ow-iw)/2:(oh-ih)/2,setsar=1" \
+    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
+    -y "$temp_concat"
+
+# ── Step 2: Speed-adjust to match music duration exactly ──────────────────────
+concat_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$temp_concat")
+speed_factor=$(echo "scale=6; $concat_dur / $music_duration" | bc)
+echo "Step 2/3: speed $speed_factor  (raw=${concat_dur}s → music=${music_duration}s)"
+
+temp_sped=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_sped")
+ffmpeg -loglevel warning \
+    -i "$temp_concat" \
+    -vf "setpts=PTS/$speed_factor" \
+    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
+    -t "$music_duration" -y "$temp_sped"
+rm "$temp_concat"
+
+# ── Step 3: Music + fades + attribution overlay ───────────────────────────────
+# Attribution overlay: semi-transparent bar across the top for the first
+# ATTR_DUR seconds, text fades in over ATTR_FADE s and out over ATTR_FADE s.
+# alpha expression: 0→1 over first ATTR_FADE s, 1 in the middle, 1→0 over
+# the last ATTR_FADE s before ATTR_DUR.
+ATTR_FADE_END=$(echo "$ATTR_DUR - $ATTR_FADE" | bc)
+ALPHA="if(lt(t,${ATTR_FADE}),t/${ATTR_FADE},if(gt(t,${ATTR_FADE_END}),(${ATTR_DUR}-t)/${ATTR_FADE},1))"
+ENABLE="between(t,0,${ATTR_DUR})"
+
+fade_out_start=$(echo "scale=3; $music_duration - $FADE_DUR" | bc)
+echo "Step 3/3: music + fades + attribution overlay..."
+
+# Build attribution drawtext filters (box=1 gives a per-line background).
+# Colons inside text values are escaped as \: (\\: in bash double-quoted strings).
+DT="drawtext=fontfile='${FONT_BOLD}'"
+DT="${DT}:text='The Four Seasons \: Antonio Vivaldi'"
+DT="${DT}:fontcolor=white:fontsize=h/22:x=(w-text_w)/2:y=h*0.012"
+DT="${DT}:box=1:boxcolor=black@0.55:boxborderw=8"
+DT="${DT}:alpha='${ALPHA}':enable='${ENABLE}'"
+
+DT="${DT},drawtext=fontfile='${FONT}'"
+DT="${DT}:text='John Harrison / Wichita State University Chamber Players'"
+DT="${DT}:fontcolor=0xEEEEEE:fontsize=h/30:x=(w-text_w)/2:y=h*0.068"
+DT="${DT}:box=1:boxcolor=black@0.55:boxborderw=6"
+DT="${DT}:alpha='${ALPHA}':enable='${ENABLE}'"
+
+DT="${DT},drawtext=fontfile='${FONT}'"
+DT="${DT}:text='Free Music Archive \: freemusicarchive.org \: CC BY-SA 3.0'"
+DT="${DT}:fontcolor=0xCCCCCC:fontsize=h/36:x=(w-text_w)/2:y=h*0.113"
+DT="${DT}:box=1:boxcolor=black@0.55:boxborderw=5"
+DT="${DT}:alpha='${ALPHA}':enable='${ENABLE}'"
+
+output_file="$output_dir/${MVT_START}_${SEASON}_Mvt${MVT_NUM}-Montage.mp4"
+
+ffmpeg -loglevel warning \
+    -i "$temp_sped" -i "$music_file" \
+    -filter_complex \
+"[0:v]fade=t=in:st=0:d=${FADE_DUR},fade=t=out:st=${fade_out_start}:d=${FADE_DUR},${DT}[vout];\
+[1:a]afade=t=in:st=0:d=${FADE_DUR},afade=t=out:st=${fade_out_start}:d=${FADE_DUR}[aout]" \
+    -map "[vout]" -map "[aout]" \
     -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 192k \
-    -t "$ATTR_DUR" -y "$temp_attr"
-
-# ── Step 5: Join montage + attribution card ───────────────────────────────────
-echo "Step 5/5: joining montage and attribution card..."
-final_list=$(mktemp --suffix=.txt); TMPFILES+=("$final_list")
-printf "file '%s'\n" "$temp_main" "$temp_attr" > "$final_list"
-
-output_file="$output_dir/$(date +%Y-%m-%d)_${SEASON}_Mvt${MVT_NUM}-Montage.mp4"
-ffmpeg -loglevel warning \
-    -f concat -safe 0 -i "$final_list" \
-    -c copy -y "$output_file"
+    -t "$music_duration" -y "$output_file"
+rm "$temp_sped"
 
 echo "Done: $output_file"
+
+# ── Notify ────────────────────────────────────────────────────────────────────
+"$SCRIPT_DIR/notify.sh" \
+    "Montage ready: $SEASON Mvt $MVT_NUM ($ASTRO_YEAR)" \
+    "$(basename "$output_file") — ${music_duration}s" \
+    || true   # notifications are best-effort
+
+# ── Trigger year-end join on last Autumn movement ────────────────────────────
+if [ "$SEASON" = "Autumn" ] && [ "$MVT_NUM" = "3" ]; then
+    echo "Last movement of astronomical year $ASTRO_YEAR — triggering year-end join..."
+    "$SCRIPT_DIR/year-end-join.sh" "$ASTRO_YEAR"
+fi
diff --git a/notify.sh b/notify.sh
new file mode 100755
index 0000000..00086ce
--- /dev/null
+++ b/notify.sh
@@ -0,0 +1,65 @@
+#!/bin/bash
+# notify.sh — send a notification via ntfy, email, and/or Mattermost.
+#
+# Usage:  notify.sh "Title" "Body message"
+#
+# Reads notify_config.txt from the same directory as this script.
+# All methods are independently enabled/disabled in the config.
+# Exits 0 even if all methods fail (notifications are best-effort).
+
+set -euo pipefail
+
+SCRIPT_DIR="$(dirname "$(realpath "$0")")"
+CONFIG="$SCRIPT_DIR/sky-cam.conf"
+
+TITLE="${1:-Sky-Cam notification}"
+BODY="${2:-}"
+
+# ── Load config ───────────────────────────────────────────────────────────────
+if [ ! -f "$CONFIG" ]; then
+    echo "notify.sh: sky-cam.conf not found — skipping notifications" >&2
+    exit 0
+fi
+
+source "$CONFIG"
+
+NTFY_ENABLED="${NTFY_ENABLED:-false}"
+NTFY_URL="${NTFY_URL:-}"
+
+EMAIL_ENABLED="${EMAIL_ENABLED:-false}"
+EMAIL_TO="${EMAIL_TO:-}"
+EMAIL_FROM="${EMAIL_FROM:-skycam@localhost}"
+
+MM_NOTIFY_ENABLED="${MM_NOTIFY_ENABLED:-false}"
+MM_NOTIFY_CHANNEL_ID="${MM_NOTIFY_CHANNEL_ID:-}"
+
+# ── ntfy ─────────────────────────────────────────────────────────────────────
+if [ "$NTFY_ENABLED" = "true" ] && [ -n "$NTFY_URL" ]; then
+    curl -s \
+        -H "Title: $TITLE" \
+        -d "$BODY" \
+        "$NTFY_URL" > /dev/null \
+        && echo "notify: ntfy sent" \
+        || echo "notify: ntfy failed" >&2
+fi
+
+# ── Email ─────────────────────────────────────────────────────────────────────
+if [ "$EMAIL_ENABLED" = "true" ] && [ -n "$EMAIL_TO" ]; then
+    echo "$BODY" | mail -s "$TITLE" -r "$EMAIL_FROM" "$EMAIL_TO" \
+        && echo "notify: email sent to $EMAIL_TO" \
+        || echo "notify: email failed" >&2
+fi
+
+# ── Mattermost text post ──────────────────────────────────────────────────────
+# mattermost_url and access_token come from sky-cam.conf (sourced above).
+if [ "$MM_NOTIFY_ENABLED" = "true" ] && [ -n "$MM_NOTIFY_CHANNEL_ID" ]; then
+    curl -s \
+        -H "Authorization: Bearer $access_token" \
+        -H "Content-Type: application/json" \
+        -d "{\"channel_id\":\"$MM_NOTIFY_CHANNEL_ID\",\"message\":\"**$TITLE**\n$BODY\"}" \
+        "${mattermost_url}/api/v4/posts" > /dev/null \
+        && echo "notify: mattermost sent" \
+        || echo "notify: mattermost failed" >&2
+fi
+
+exit 0
diff --git a/season_info.py b/season_info.py
index 8cb13c8..12e267c 100644
--- a/season_info.py
+++ b/season_info.py
@@ -28,6 +28,9 @@ Outputs (shell-sourceable):
     SEASON_START   YYYY-MM-DD of season start   (local date)
     SEASON_END     YYYY-MM-DD of season end     (local date)
     IS_LAST_DAY    true | false
+    ASTRO_YEAR     year when the current cycle's Winter solstice occurred
+                   (Spring/Summer/Autumn of 2026 all return 2025 if Winter
+                   started Dec 2025; Winter 2025 itself also returns 2025)
 """
 
 import sys
@@ -148,6 +151,11 @@ def get_info(date: datetime.date, tz_name: str = DEFAULT_TZ) -> dict:
     else:
         mvt, mvt_start, mvt_end, days_in_mvt = 3, m2_end + datetime.timedelta(1), m3_end, m3
 
+    # Astronomical year: the calendar year in which the current cycle's Winter
+    # solstice occurred.  Spring/Summer/Autumn belong to the Winter that preceded
+    # them; Winter belongs to the solstice that started it.
+    astro_year = s_start.year if season == "Winter" else prev["Winter"].year
+
     return {
         "SEASON":       season,
         "MVT_NUM":      mvt,
@@ -158,6 +166,7 @@ def get_info(date: datetime.date, tz_name: str = DEFAULT_TZ) -> dict:
         "SEASON_START": s_start.isoformat(),
         "SEASON_END":   s_end.isoformat(),
         "IS_LAST_DAY":  str(date == mvt_end).lower(),
+        "ASTRO_YEAR":   str(astro_year),
     }
 
 
diff --git a/sky-cam.conf b/sky-cam.conf
new file mode 100644
index 0000000..ef170a0
--- /dev/null
+++ b/sky-cam.conf
@@ -0,0 +1,33 @@
+# sky-cam.conf — single config for all sky-cam scripts and Python helpers.
+#
+# Bash scripts source this file:
+#   source "$(dirname "$(realpath "$0")")/sky-cam.conf"
+#
+# Python reads it with key=value parsing (same format, quotes stripped).
+#
+# Copy this file to your scripts directory and fill in every value.
+# Lines starting with # are comments and are ignored.
+
+# ── Paths ─────────────────────────────────────────────────────────────────────
+BASE_DIR=/home/motion/drives/local-2tb
+MUSIC_DIR=/home/motion/drives/local-2tb/music/4 Seasons
+TIMEZONE=America/New_York
+
+# ── Mattermost — daily sunrise upload ────────────────────────────────────────
+mattermost_url=https://your-mattermost-server.example.com
+access_token=your-access-token-here
+channel_id=your-daily-upload-channel-id-here
+
+# ── Notifications — movement montage + year-end video complete / job failure ──
+# ntfy: https://ntfy.sh (cloud) or self-hosted.  Set topic URL below.
+NTFY_ENABLED=false
+NTFY_URL=https://ntfy.sh/your-topic-here
+
+# Email: requires the 'mail' command (mailutils / s-nail).
+EMAIL_ENABLED=false
+EMAIL_TO=you@example.com
+EMAIL_FROM=skycam@localhost
+
+# Mattermost text post (can be same channel as daily upload or a private one).
+MM_NOTIFY_ENABLED=false
+MM_NOTIFY_CHANNEL_ID=your-notify-channel-id-here
diff --git a/stitch-cameras.py b/stitch-cameras.py
index 55f6701..eaeb0b2 100644
--- a/stitch-cameras.py
+++ b/stitch-cameras.py
@@ -1,79 +1,173 @@
 #!/usr/bin/env python3
 """
-Final stitch: north left, sunrise right.
-Translation from phase-correlation (tx=-3324, ty=-85).
-Feathered gradient blend across the overlap zone.
+Stitch north (cylindrical warp) + sunrise (unmodified).
+
+Usage:
+  python3 stitch-cameras.py north.jpg sunrise.jpg out_prefix [focal_px]
+
+  focal_px: cylindrical focal length in pixels (default: auto-search).
+            Approx guide: 1920 = ~90° HFOV for a 3840px-wide sensor.
+
+Pipeline
+--------
+1. Cylindrical-warp north only; sunrise is never modified.
+2. Build a soft validity mask for the warped north so black-corner
+   pixels fade out smoothly.
+3. Phase-correlate edge-enhanced treeline strips to find tx, ty.
+4. Colour-match north's overlap strip to sunrise's (per-channel gain)
+   so the two cameras' exposure/WB differences don't leave a visible seam.
+5. Feathered alpha blend in the overlap zone, weighted by north's validity.
+6. Crop black margins; output full-res panorama + half-size preview.
 """
 import sys, cv2, numpy as np
 
-north_p, sunrise_p, out_p = sys.argv[1], sys.argv[2], sys.argv[3]
-tx_arg = int(sys.argv[4]) if len(sys.argv) > 4 else -3324
-ty_arg = int(sys.argv[5]) if len(sys.argv) > 5 else -85
+north_p  = sys.argv[1]
+sunrise_p= sys.argv[2]
+prefix   = sys.argv[3]
+forced_f = float(sys.argv[4]) if len(sys.argv) > 4 else None
 
 north   = cv2.imread(north_p)
 sunrise = cv2.imread(sunrise_p)
+assert north is not None,  f"Cannot read {north_p}"
+assert sunrise is not None, f"Cannot read {sunrise_p}"
 H, W = north.shape[:2]
+cx, cy = W / 2.0, H / 2.0
 
-tx, ty = tx_arg, ty_arg   # north → sunrise translation
-print(f"Using tx={tx}  ty={ty}")
+# ── Helpers ───────────────────────────────────────────────────────────────────
 
-# ── Canvas ────────────────────────────────────────────────────────────────────
-# Sunrise is at the canvas origin (0,0).
-# North is at (tx, ty) relative to sunrise — tx is negative so north is LEFT.
-canvas_x0 = min(0, tx)          # leftmost pixel
-canvas_y0 = min(0, ty)
-canvas_x1 = max(W, W + tx)
-canvas_y1 = max(H, H + ty)
-cW = int(canvas_x1 - canvas_x0)
-cH = int(canvas_y1 - canvas_y0)
+def cylindrical_warp(img, f):
+    xc = np.arange(W, dtype=np.float32) - cx
+    yc = np.arange(H, dtype=np.float32) - cy
+    XC, YC = np.meshgrid(xc, yc)
+    theta = XC / f
+    map_x = (f * np.tan(theta) + cx).astype(np.float32)
+    map_y = (YC / np.cos(theta) + cy).astype(np.float32)
+    warped = cv2.remap(img, map_x, map_y, cv2.INTER_LINEAR,
+                       borderMode=cv2.BORDER_CONSTANT, borderValue=0)
+    valid = ((map_x >= 0) & (map_x < W) &
+             (map_y >= 0) & (map_y < H)).astype(np.float32)
+    return warped, valid
 
-# Canvas offsets for each image
-s_ox, s_oy = int(-canvas_x0), int(-canvas_y0)   # sunrise top-left in canvas
-n_ox, n_oy = s_ox + tx, s_oy + ty                # north top-left in canvas
+def phase_corr(n_cyl):
+    """Return (peak_score, tx, ty) aligning warped-north to sunrise."""
+    bw = int(W * 0.35)
+    y0, y1 = int(H * 0.60), int(H * 0.92)
+    n_strip = cv2.cvtColor(n_cyl  [:, W-bw:], cv2.COLOR_BGR2GRAY)[y0:y1].astype(np.float64)
+    s_strip = cv2.cvtColor(sunrise[:, :bw],   cv2.COLOR_BGR2GRAY)[y0:y1].astype(np.float64)
+    ne = cv2.Laplacian(n_strip, cv2.CV_64F, ksize=3)
+    se = cv2.Laplacian(s_strip, cv2.CV_64F, ksize=3)
+    N = np.fft.fft2(ne); S = np.fft.fft2(se)
+    R = N * np.conj(S); nrm = np.abs(R); nrm[nrm == 0] = 1
+    corr = np.fft.ifft2(R / nrm).real
+    peak_val = corr.max()
+    dy_r, dx_r = [int(v) for v in np.unravel_index(np.argmax(corr), corr.shape)]
+    rh, rw = corr.shape
+    if dy_r > rh // 2: dy_r -= rh
+    if dx_r > rw // 2: dx_r -= rw
+    return peak_val, -(W - bw + dx_r), -dy_r
 
-canvas = np.zeros((cH, cW, 3), dtype=np.uint8)
+def colour_match(src, ref_strip_src, ref_strip_ref):
+    """Scale each BGR channel of src so strip means match between the two strips."""
+    out = src.astype(np.float32)
+    for c in range(3):
+        s_mean = ref_strip_src[..., c].astype(np.float32).mean()
+        r_mean = ref_strip_ref[..., c].astype(np.float32).mean()
+        gain = np.clip(r_mean / s_mean if s_mean > 1e-3 else 1.0, 0.5, 2.0)
+        out[..., c] = np.clip(out[..., c] * gain, 0, 255)
+    return out
 
-# Paint north first (background)
-nx0, ny0 = int(n_ox), int(n_oy)
-canvas[ny0:ny0+H, nx0:nx0+W] = north
+# ── Focal length search (or forced) ──────────────────────────────────────────
+focal_candidates = [forced_f] if forced_f else [1400, 1550, 1700, 1800, 1920, 2100, 2300, 2600]
+print(f"{'focal':>6}  {'score':>8}  {'tx':>7}  {'ty':>5}")
+best_score, best_f, best_tx, best_ty = -1.0, 1920.0, 0, 0
+for f in focal_candidates:
+    n_cyl, _ = cylindrical_warp(north, f)
+    score, tx, ty = phase_corr(n_cyl)
+    print(f"{f:6.0f}  {score:8.5f}  {tx:7d}  {ty:5d}")
+    if score > best_score:
+        best_score, best_f, best_tx, best_ty = score, f, tx, ty
 
-# Paint sunrise on top (base)
-sx0, sy0 = int(s_ox), int(s_oy)
-canvas[sy0:sy0+H, sx0:sx0+W] = sunrise
+f   = best_f
+tx  = best_tx
+ty  = best_ty
+print(f"\nBest focal={f:.0f}  score={best_score:.5f}  tx={tx}  ty={ty}")
 
-# ── Feathered blend in overlap zone ──────────────────────────────────────────
-# Overlap: columns where both images exist in the canvas
-ov_x0 = max(sx0, nx0)
-ov_x1 = min(sx0 + W, nx0 + W)
-ov_y0 = max(sy0, ny0)
-ov_y1 = min(sy0 + H, ny0 + H)
+# ── Warp + validity mask ──────────────────────────────────────────────────────
+n_cyl, valid_raw = cylindrical_warp(north, f)
 
+kernel      = np.ones((31, 31), np.float32) / (31 * 31)
+valid_soft  = cv2.filter2D(valid_raw, -1, kernel).clip(0, 1)
+
+# First column of north with >50% valid pixels in the central band
+central_y0, central_y1 = int(H * 0.10), int(H * 0.90)
+col_valid = valid_raw[central_y0:central_y1, :].mean(axis=0)
+first_valid_col = int(np.argmax(col_valid > 0.5))
+
+# ── Canvas geometry ───────────────────────────────────────────────────────────
+xmin = min(0, tx); ymin = min(0, ty)
+xmax = max(W, W + tx); ymax = max(H, H + ty)
+cW, cH = int(xmax - xmin), int(ymax - ymin)
+sx0, sy0 = int(-xmin), int(-ymin)
+nx0, ny0 = int(sx0 + tx), int(sy0 + ty)
+
+ov_x0 = max(sx0, nx0);  ov_x1 = min(sx0 + W, nx0 + W)
+ov_y0 = max(sy0, ny0);  ov_y1 = min(sy0 + H, ny0 + H)
+
+# ── Colour-match north → sunrise in the overlap strip ────────────────────────
+# Use a central vertical slice of the overlap (avoid the edge-feather zones).
+ov_w = ov_x1 - ov_x0
+# Sample the middle half of the overlap, treeline rows only (avoid sky + timestamp)
+y_lo, y_hi = int(H * 0.55), int(H * 0.88)
+mid_n_x0 = ov_x0 - nx0 + ov_w // 4
+mid_n_x1 = ov_x0 - nx0 + 3 * ov_w // 4
+mid_s_x0 = ov_x0 - sx0 + ov_w // 4
+mid_s_x1 = ov_x0 - sx0 + 3 * ov_w // 4
+n_sample = n_cyl  [y_lo:y_hi, mid_n_x0:mid_n_x1]
+s_sample = sunrise[y_lo:y_hi, mid_s_x0:mid_s_x1]
+n_cyl_matched = colour_match(n_cyl, n_sample, s_sample)
+print(f"Colour-matched north to sunrise (overlap centre rows {y_lo}-{y_hi})")
+
+# ── Composite ────────────────────────────────────────────────────────────────
+canvas = np.zeros((cH, cW, 3), dtype=np.float32)
+
+# 1. Paint north (valid content only, black corners excluded)
+nv   = valid_soft[..., np.newaxis]
+c_s  = nx0 + first_valid_col
+c_e  = min(nx0 + W, cW)
+canvas[ny0:ny0 + H, c_s:c_e] = (
+    n_cyl_matched[:, first_valid_col:c_e - nx0].astype(np.float32)
+    * nv[:, first_valid_col:c_e - nx0]
+)
+
+# 2. Sunrise overwrites its entire area (completely unmodified)
+canvas[sy0:sy0 + H, sx0:sx0 + W] = sunrise.astype(np.float32)
+
+# 3. Feathered blend in overlap: when north is invalid, fall back to sunrise
 if ov_x1 > ov_x0 and ov_y1 > ov_y0:
     ov_w = ov_x1 - ov_x0
-    ov_h = ov_y1 - ov_y0
-    print(f"Overlap zone: {ov_w}x{ov_h}px  at canvas x=[{ov_x0},{ov_x1}]")
+    alpha    = np.linspace(0.0, 1.0, ov_w, dtype=np.float32)[np.newaxis, :, np.newaxis]
+    n_patch  = n_cyl_matched[ov_y0 - ny0:ov_y1 - ny0, ov_x0 - nx0:ov_x1 - nx0].astype(np.float32)
+    s_patch  = sunrise      [ov_y0 - sy0:ov_y1 - sy0, ov_x0 - sx0:ov_x1 - sx0].astype(np.float32)
+    nv_patch = valid_soft   [ov_y0 - ny0:ov_y1 - ny0, ov_x0 - nx0:ov_x1 - nx0][..., np.newaxis]
+    s_weight = np.maximum(alpha, 1.0 - nv_patch)
+    canvas[ov_y0:ov_y1, ov_x0:ov_x1] = s_patch * s_weight + n_patch * (1.0 - s_weight)
+    print(f"Overlap blend: {ov_w}x{ov_y1 - ov_y0}px")
 
-    # Horizontal gradient: sunrise fades OUT on the left (where north takes over)
-    #                       north   fades OUT on the right (where sunrise takes over)
-    alpha = np.linspace(0.0, 1.0, ov_w, dtype=np.float32)   # 0=north, 1=sunrise
-    alpha = alpha[np.newaxis, :, np.newaxis]                 # shape (1, ov_w, 1)
+out = canvas.clip(0, 255).astype(np.uint8)
 
-    n_patch = north  [ov_y0-ny0:ov_y1-ny0, ov_x0-nx0:ov_x1-nx0].astype(np.float32)
-    s_patch = sunrise[ov_y0-sy0:ov_y1-sy0, ov_x0-sx0:ov_x1-sx0].astype(np.float32)
-    blended = (s_patch * alpha + n_patch * (1.0 - alpha)).astype(np.uint8)
-    canvas[ov_y0:ov_y1, ov_x0:ov_x1] = blended
+# Vertical crop to rows where both images exist
+top = max(sy0, ny0); bot = min(sy0 + H, ny0 + H)
+out = out[top:bot, :]
 
-# ── Crop off the black margin at top/bottom from the ty offset ───────────────
-# After the shift there may be a thin black bar top or bottom — crop it.
-top_crop    = max(sy0, ny0)           # first row where BOTH images exist
-bottom_crop = min(sy0+H, ny0+H)      # last row where either image exists
-canvas = canvas[top_crop:bottom_crop, :]
+# Left-crop black corner columns
+col_has_content = out.max(axis=(0, 2)) > 0
+left_crop = int(np.argmax(col_has_content))
+out = out[:, left_crop:]
+print(f"Final size: {out.shape[1]}x{out.shape[0]}")
 
-cv2.imwrite(out_p, canvas, [cv2.IMWRITE_JPEG_QUALITY, 92])
-print(f"Output: {out_p}  size={canvas.shape[1]}x{canvas.shape[0]}")
+cv2.imwrite(f"{prefix}-panorama.jpg", out, [cv2.IMWRITE_JPEG_QUALITY, 93])
+half = cv2.resize(out, (out.shape[1] // 2, out.shape[0] // 2))
+cv2.imwrite(f"{prefix}-preview.jpg", half, [cv2.IMWRITE_JPEG_QUALITY, 88])
 
-# ── Save a 50% scaled preview for quick viewing ───────────────────────────────
-preview = cv2.resize(canvas, (canvas.shape[1]//2, canvas.shape[0]//2))
-cv2.imwrite(out_p.replace(".jpg", "-preview.jpg"), preview,
-            [cv2.IMWRITE_JPEG_QUALITY, 85])
-print(f"Preview saved.")
+with open(f"{prefix}-params.txt", "w") as fh:
+    fh.write(f"focal={f:.0f}\ntx={tx}\nty={ty}\n")
diff --git a/sunrise2mm.py b/sunrise2mm.py
index 484f56c..e6ad9d5 100644
--- a/sunrise2mm.py
+++ b/sunrise2mm.py
@@ -2,8 +2,11 @@ import requests
 import os
 from datetime import datetime
 
-# Configuration file path (update the path to where your mattermost_config.txt is located)
-config_file_path = '/home/motion/drives/local-2tb/sunrise-scripts/mattermost_config.txt'
+import pathlib
+
+# Locate sky-cam.conf next to this script (works regardless of cwd).
+_here = pathlib.Path(__file__).resolve().parent
+config_file_path = str(_here / 'sky-cam.conf')
 
 # Function to read configuration from the config file
 def read_config(config_file_path):
diff --git a/systemd/README.txt b/systemd/README.txt
new file mode 100644
index 0000000..1f1b94a
--- /dev/null
+++ b/systemd/README.txt
@@ -0,0 +1,40 @@
+Installing systemd timers
+========================
+
+1. Edit the ExecStart paths in each .service file to match where your scripts live.
+
+2. Copy units to the systemd user directory (no root needed):
+
+    mkdir -p ~/.config/systemd/user
+    cp sky-cam-*.service sky-cam-*.timer ~/.config/systemd/user/
+
+   Or system-wide (root required):
+
+    sudo cp sky-cam-*.service sky-cam-*.timer /etc/systemd/system/
+
+3. Reload and enable:
+
+    # User-level
+    systemctl --user daemon-reload
+    systemctl --user enable --now sky-cam-sunrise.timer
+    systemctl --user enable --now sky-cam-4seasons.timer
+    systemctl --user enable --now sky-cam-fullday.timer
+
+    # System-level (replace --user with no flag, add sudo)
+    sudo systemctl daemon-reload
+    sudo systemctl enable --now sky-cam-sunrise.timer
+    ...
+
+4. Check status:
+
+    systemctl --user list-timers sky-cam-*
+    journalctl --user -u sky-cam-4seasons.service -f
+
+Notes
+-----
+- Persistent=true means missed runs (e.g. system was off at 01:00) are
+  caught up on next boot, within the same day.
+- montage-mvt.sh and year-end-join.sh are NOT scheduled directly — they
+  are triggered automatically by 4-seasons.sh on the appropriate days.
+- notify.sh fires inside montage-mvt.sh and year-end-join.sh; it is not
+  a separate scheduled job.
diff --git a/systemd/sky-cam-4seasons.service b/systemd/sky-cam-4seasons.service
new file mode 100644
index 0000000..0f0347f
--- /dev/null
+++ b/systemd/sky-cam-4seasons.service
@@ -0,0 +1,11 @@
+[Unit]
+Description=Sky-Cam Four Seasons daily clip (+ montage trigger on last day)
+After=network-online.target
+Wants=network-online.target
+OnFailure=sky-cam-notify-failure@%n.service
+
+[Service]
+Type=oneshot
+ExecStart=/home/motion/drives/local-2tb/sunrise-scripts/4-seasons.sh
+StandardOutput=journal
+StandardError=journal
diff --git a/systemd/sky-cam-4seasons.timer b/systemd/sky-cam-4seasons.timer
new file mode 100644
index 0000000..b6f5928
--- /dev/null
+++ b/systemd/sky-cam-4seasons.timer
@@ -0,0 +1,9 @@
+[Unit]
+Description=Sky-Cam Four Seasons daily clip — 01:00
+
+[Timer]
+OnCalendar=*-*-* 01:00:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
diff --git a/systemd/sky-cam-fullday.service b/systemd/sky-cam-fullday.service
new file mode 100644
index 0000000..bef3263
--- /dev/null
+++ b/systemd/sky-cam-fullday.service
@@ -0,0 +1,9 @@
+[Unit]
+Description=Sky-Cam full-day timelapse (10-day retention)
+OnFailure=sky-cam-notify-failure@%n.service
+
+[Service]
+Type=oneshot
+ExecStart=/home/motion/drives/local-2tb/sunrise-scripts/fullday-video.sh
+StandardOutput=journal
+StandardError=journal
diff --git a/systemd/sky-cam-fullday.timer b/systemd/sky-cam-fullday.timer
new file mode 100644
index 0000000..e47a900
--- /dev/null
+++ b/systemd/sky-cam-fullday.timer
@@ -0,0 +1,9 @@
+[Unit]
+Description=Sky-Cam full-day timelapse — 02:00
+
+[Timer]
+OnCalendar=*-*-* 02:00:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
diff --git a/systemd/sky-cam-notify-failure@.service b/systemd/sky-cam-notify-failure@.service
new file mode 100644
index 0000000..08cd719
--- /dev/null
+++ b/systemd/sky-cam-notify-failure@.service
@@ -0,0 +1,10 @@
+[Unit]
+Description=Sky-Cam failure notification for %i
+
+[Service]
+Type=oneshot
+# %i is the name of the failed unit (passed by OnFailure=)
+# Edit ExecStart path to match your install location.
+ExecStart=/home/motion/drives/local-2tb/sunrise-scripts/notify.sh \
+    "sky-cam job failed: %i" \
+    "systemd unit %i exited with failure. Check logs: journalctl -u %i"
diff --git a/systemd/sky-cam-sunrise.service b/systemd/sky-cam-sunrise.service
new file mode 100644
index 0000000..2f58c2d
--- /dev/null
+++ b/systemd/sky-cam-sunrise.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Sky-Cam daily sunrise video → Mattermost
+After=network-online.target
+Wants=network-online.target
+OnFailure=sky-cam-notify-failure@%n.service
+
+[Service]
+Type=oneshot
+# ── Edit this path ────────────────────────────────────────────────────────────
+ExecStart=/home/motion/drives/local-2tb/sunrise-scripts/sunrise_video.10s.sh
+StandardOutput=journal
+StandardError=journal
diff --git a/systemd/sky-cam-sunrise.timer b/systemd/sky-cam-sunrise.timer
new file mode 100644
index 0000000..f047a2f
--- /dev/null
+++ b/systemd/sky-cam-sunrise.timer
@@ -0,0 +1,11 @@
+[Unit]
+Description=Sky-Cam sunrise video — daily at 09:00
+
+[Timer]
+# Run at 09:00 every day (after sunrise window has ended).
+OnCalendar=*-*-* 09:00:00
+# If the system was off at 09:00, run as soon as it boots (within 1 hour).
+Persistent=true
+
+[Install]
+WantedBy=timers.target
diff --git a/year-end-join.sh b/year-end-join.sh
new file mode 100755
index 0000000..f0ad1ab
--- /dev/null
+++ b/year-end-join.sh
@@ -0,0 +1,78 @@
+#!/bin/bash
+# year-end-join.sh — concatenate all 12 movement montages for one astronomical
+# year into a single "Four Seasons" video.
+#
+# Called automatically by montage-mvt.sh after the last Autumn movement finishes.
+# Can also be run manually:  ./year-end-join.sh 2025
+#
+# The 12 individual movement videos already carry their own attribution overlay
+# (first 6 seconds of each), so no extra card is appended here.
+#
+# Output: $base_dir/movies/$script_name/$ASTRO_YEAR/$script_name-$ASTRO_YEAR.mp4
+
+set -euo pipefail
+
+SCRIPT_DIR="$(dirname "$(realpath "$0")")"
+source "$SCRIPT_DIR/sky-cam.conf"
+
+ASTRO_YEAR="${1:-}"
+if [ -z "$ASTRO_YEAR" ]; then
+    echo "Usage: $0 <ASTRO_YEAR>  (e.g. $0 2025)"
+    exit 1
+fi
+
+base_dir="$BASE_DIR"
+script_name=$(basename "$SCRIPT_DIR" | cut -d'-' -f1)
+year_dir="$base_dir/movies/$script_name/$ASTRO_YEAR"
+
+echo "Assembling Four Seasons $ASTRO_YEAR from $year_dir ..."
+
+# ── Collect the 12 montage files in season/movement order ────────────────────
+concat_list=$(mktemp --suffix=.txt)
+trap 'rm -f "$concat_list"' EXIT
+
+missing=0
+for season in Winter Spring Summer Autumn; do
+    for mvt in 1 2 3; do
+        mvt_dir="$year_dir/$season/Mvt$mvt/montage"
+        # Pick the newest (or only) montage file for this movement
+        f=$(find "$mvt_dir" -maxdepth 1 -name "*-Montage.mp4" 2>/dev/null | sort | tail -1)
+        if [ -z "$f" ]; then
+            echo "WARNING: missing montage for $season Mvt$mvt ($mvt_dir)"
+            missing=$((missing + 1))
+        else
+            echo "  $season Mvt$mvt → $(basename "$f")"
+            printf "file '%s'\n" "$f" >> "$concat_list"
+        fi
+    done
+done
+
+found=$(wc -l < "$concat_list")
+echo "$found of 12 movements found  ($missing missing)"
+
+if [ "$found" -eq 0 ]; then
+    echo "ERROR: no montage files found — aborting."
+    exit 1
+fi
+
+if [ "$missing" -gt 0 ]; then
+    echo "WARNING: joining with $missing movement(s) absent."
+fi
+
+# ── Join ──────────────────────────────────────────────────────────────────────
+output_file="$year_dir/${script_name}-${ASTRO_YEAR}.mp4"
+echo "Output: $output_file"
+
+ffmpeg -loglevel warning \
+    -f concat -safe 0 -i "$concat_list" \
+    -c copy -y "$output_file"
+
+total_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$output_file")
+total_min=$(echo "scale=1; $total_dur / 60" | bc)
+echo "Done: $output_file  (${total_min} min)"
+
+# ── Notify ────────────────────────────────────────────────────────────────────
+"$SCRIPT_DIR/notify.sh" \
+    "Four Seasons $ASTRO_YEAR complete" \
+    "${script_name}-${ASTRO_YEAR}.mp4 — ${total_min} minutes  ($found movements)" \
+    || true