fix(scripts): kevin-analyze + reanalyze — self-contained + append-only

Two small follow-ups from the session:

- kevin-analyze.sh: always cp the local analyze_kevin_video.py into
  the pod before exec, so the wrapper works even before CI ships an
  image with scripts/ baked in (saw this hit the user with
  ModuleNotFoundError on stale images).

- reanalyze_kevin_videos.py: switch from DELETE+INSERT to
  append-only. The old behaviour violated the FK constraint on
  kevin_signal_bridge_state.mention_id; the new behaviour adds a
  fresh v2 analysis alongside the v1 row and lets the API surface
  the latest. Old v1 rows preserved for audit.

scripts/kevin-analyze.sh

@@ -5,8 +5,9 @@
 #   ./scripts/kevin-analyze.sh <video-id-or-url>
 #
 # Picks the running meet-kevin-watcher container (which already has
-# yt-dlp + ffmpeg + the Anthropic token + the right Python env) and
-# runs scripts/analyze_kevin_video.py inside it.
+# yt-dlp + ffmpeg + the Anthropic token + the right Python env), copies
+# the local script in, and runs it. Works regardless of whether the
+# image has scripts/ baked in yet.
 
 set -euo pipefail
 
@@ -15,6 +16,14 @@ if [[ $# -ne 1 ]]; then
     exit 1
 fi
 
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+LOCAL_SCRIPT="$SCRIPT_DIR/analyze_kevin_video.py"
+
+if [[ ! -f "$LOCAL_SCRIPT" ]]; then
+    echo "missing $LOCAL_SCRIPT" >&2
+    exit 1
+fi
+
 POD=$(kubectl -n trading-bot get pod -l app=trading-bot-workers \
     -o jsonpath='{.items[0].metadata.name}')
 
@@ -23,5 +32,10 @@ if [[ -z "$POD" ]]; then
     exit 1
 fi
 
+# Copy the latest local script into the pod, then exec it. This way the
+# wrapper works even before CI ships an image with scripts/ baked in.
+kubectl -n trading-bot cp "$LOCAL_SCRIPT" \
+    "$POD:/tmp/kevin-analyze.py" -c meet-kevin-watcher >/dev/null
+
 exec kubectl -n trading-bot exec "$POD" -c meet-kevin-watcher -- \
-    python -m scripts.analyze_kevin_video "$1"
+    python /tmp/kevin-analyze.py "$1"