fix: init script captures wrong session IDs when old sessions exist

The init script used 'tail -1' to find newly created sessions, which
fails when old sessions exist because it picks an existing session
instead of the newly created one.

The fix captures session IDs before and after creating new sessions,
then diffs to identify newly created sessions.

Fixes #172

skills/kugetsu/scripts/kugetsu-session.sh

@@ -81,9 +81,20 @@ EOF
     echo "Press Ctrl+C to cancel or wait for session to be created"
     sleep 2
 
+    local before_sessions=$(opencode session list 2>/dev/null | grep -E '^ses_' | awk '{print $1}' || true)
+
     opencode
 
-    local session_ids=$(opencode session list 2>/dev/null | grep -E '^ses_' | awk '{print $1}' | tail -1)
+    local after_sessions=$(opencode session list 2>/dev/null | grep -E '^ses_' | awk '{print $1}' || true)
+    local session_ids=""
+    while IFS= read -r line; do
+        local sid=$(echo "$line" | awk '{print $1}')
+        if [ -n "$sid" ] && ! echo "$before_sessions" | grep -q "^${sid}$"; then
+            session_ids="$sid"
+            break
+        fi
+    done <<< "$after_sessions"
+
     if [ -z "$session_ids" ]; then
         echo "Error: Could not find newly created session" >&2
         exit 1
@@ -95,9 +106,20 @@ EOF
     echo "Base session created: $session_ids"
     echo "Starting PM agent..."
 
+    before_sessions="$after_sessions"
+
     opencode
 
-    local pm_session_ids=$(opencode session list 2>/dev/null | grep -E '^ses_' | grep -v "$session_ids" | tail -1)
+    after_sessions=$(opencode session list 2>/dev/null | grep -E '^ses_' | awk '{print $1}' || true)
+    local pm_session_ids=""
+    while IFS= read -r line; do
+        local sid=$(echo "$line" | awk '{print $1}')
+        if [ -n "$sid" ] && ! echo "$before_sessions" | grep -q "^${sid}$"; then
+            pm_session_ids="$sid"
+            break
+        fi
+    done <<< "$after_sessions"
+
     if [ -z "$pm_session_ids" ]; then
         echo "Warning: Could not find separate PM agent session" >&2
         pm_session_ids="$session_ids"