fix(session): address code review feedback for session management

- Fix SC2155: separate declare from assign in get_session_id(),
  log_session_transition(), init_session_tracking()
- Use jq for safe JSON generation in reset_session() and init_session_tracking()
  instead of heredocs (prevents special character issues)
- Add corruption tolerance to log_session_transition() with JSON validation
  and fallback to empty array on parse failures
- Add generate_session_id() to create unique session IDs (ralph-<epoch>-<random>)
- Add update_session_last_used() helper called on each loop iteration
- init_session_tracking() now generates unique session_id and sets last_used
- Add session files to .gitignore (.ralph_session, .ralph_session_history,
  .claude_session_id)

All 265 tests pass.

.gitignore

@@ -3,6 +3,9 @@
 .last_reset
 .exit_signals
 status.json
+.ralph_session
+.ralph_session_history
+.claude_session_id
 
 # Logs
 logs/*

ralph_loop.sh

@@ -494,9 +494,13 @@ get_session_id() {
         return 0
     fi
 
-    # Extract session_id from JSON file
+    # Extract session_id from JSON file (SC2155: separate declare from assign)
-    local session_id=$(jq -r '.session_id // ""' "$RALPH_SESSION_FILE" 2>/dev/null)
+    local session_id
-    if [[ "$session_id" == "null" ]]; then
+    session_id=$(jq -r '.session_id // ""' "$RALPH_SESSION_FILE" 2>/dev/null)
+    local jq_status=$?
+
+    # Handle jq failure or null/empty results
+    if [[ $jq_status -ne 0 || -z "$session_id" || "$session_id" == "null" ]]; then
         session_id=""
     fi
     echo "$session_id"
@@ -508,22 +512,30 @@ get_session_id() {
 reset_session() {
     local reason=${1:-"manual_reset"}
 
-    # Always create/overwrite the session file to ensure consistent state
+    # Get current timestamp
-    cat > "$RALPH_SESSION_FILE" << EOF
+    local reset_timestamp
-{
+    reset_timestamp=$(get_iso_timestamp)
-    "session_id": "",
+
-    "created_at": "",
+    # Always create/overwrite the session file using jq for safe JSON escaping
-    "last_used": "",
+    jq -n \
-    "reset_at": "$(get_iso_timestamp)",
+        --arg session_id "" \
-    "reset_reason": "$reason"
+        --arg created_at "" \
-}
+        --arg last_used "" \
-EOF
+        --arg reset_at "$reset_timestamp" \
+        --arg reset_reason "$reason" \
+        '{
+            session_id: $session_id,
+            created_at: $created_at,
+            last_used: $last_used,
+            reset_at: $reset_at,
+            reset_reason: $reset_reason
+        }' > "$RALPH_SESSION_FILE"
 
     # Also clear the Claude session file for consistency
     rm -f "$CLAUDE_SESSION_FILE" 2>/dev/null
 
-    # Log the session transition
+    # Log the session transition (non-fatal to prevent script exit under set -e)
-    log_session_transition "active" "reset" "$reason" "${loop_count:-0}"
+    log_session_transition "active" "reset" "$reason" "${loop_count:-0}" || true
 
     log_status "INFO" "Session reset: $reason"
 }
@@ -536,15 +548,14 @@ log_session_transition() {
     local reason=$3
     local loop_number=${4:-0}
 
-    # Initialize history file if needed
+    # Get timestamp once (SC2155: separate declare from assign)
-    if [[ ! -f "$RALPH_SESSION_HISTORY_FILE" ]]; then
+    local ts
-        echo '[]' > "$RALPH_SESSION_HISTORY_FILE"
+    ts=$(get_iso_timestamp)
-    fi
 
-    # Create transition entry
+    # Create transition entry using jq for safe JSON (SC2155: separate declare from assign)
     local transition
-    transition=$(jq -n \
+    transition=$(jq -n -c \
-        --arg timestamp "$(get_iso_timestamp)" \
+        --arg timestamp "$ts" \
         --arg from_state "$from_state" \
         --arg to_state "$to_state" \
         --arg reason "$reason" \
@@ -557,40 +568,107 @@ log_session_transition() {
             loop_number: $loop_number
         }')
 
-    # Append to history and keep only last 50 entries
+    # Read history file defensively - fallback to empty array on any failure
-    local history=$(cat "$RALPH_SESSION_HISTORY_FILE" 2>/dev/null || echo '[]')
+    local history
-    history=$(echo "$history" | jq ". += [$transition] | .[-50:]")
+    if [[ -f "$RALPH_SESSION_HISTORY_FILE" ]]; then
-    echo "$history" > "$RALPH_SESSION_HISTORY_FILE"
+        history=$(cat "$RALPH_SESSION_HISTORY_FILE" 2>/dev/null)
+        # Validate JSON, fallback to empty array if corrupted
+        if ! echo "$history" | jq empty 2>/dev/null; then
+            history='[]'
+        fi
+    else
+        history='[]'
+    fi
+
+    # Append transition and keep only last 50 entries
+    local updated_history
+    updated_history=$(echo "$history" | jq ". += [$transition] | .[-50:]" 2>/dev/null)
+    local jq_status=$?
+
+    # Only write if jq succeeded
+    if [[ $jq_status -eq 0 && -n "$updated_history" ]]; then
+        echo "$updated_history" > "$RALPH_SESSION_HISTORY_FILE"
+    else
+        # Fallback: start fresh with just this transition
+        echo "[$transition]" > "$RALPH_SESSION_HISTORY_FILE"
+    fi
+}
+
+# Generate a unique session ID using timestamp and random component
+generate_session_id() {
+    local ts
+    ts=$(date +%s)
+    local rand
+    rand=$RANDOM
+    echo "ralph-${ts}-${rand}"
 }
 
 # Initialize session tracking (called at loop start)
 init_session_tracking() {
+    local ts
+    ts=$(get_iso_timestamp)
+
     # Create session file if it doesn't exist
     if [[ ! -f "$RALPH_SESSION_FILE" ]]; then
-        cat > "$RALPH_SESSION_FILE" << EOF
+        local new_session_id
-{
+        new_session_id=$(generate_session_id)
-    "session_id": "",
+
-    "created_at": "$(get_iso_timestamp)",
+        jq -n \
-    "last_used": "",
+            --arg session_id "$new_session_id" \
-    "reset_at": "",
+            --arg created_at "$ts" \
-    "reset_reason": ""
+            --arg last_used "$ts" \
-}
+            --arg reset_at "" \
-EOF
+            --arg reset_reason "" \
-        log_status "INFO" "Initialized session tracking"
+            '{
+                session_id: $session_id,
+                created_at: $created_at,
+                last_used: $last_used,
+                reset_at: $reset_at,
+                reset_reason: $reset_reason
+            }' > "$RALPH_SESSION_FILE"
+
+        log_status "INFO" "Initialized session tracking (session: $new_session_id)"
+        return 0
     fi
 
     # Validate existing session file
     if ! jq empty "$RALPH_SESSION_FILE" 2>/dev/null; then
         log_status "WARN" "Corrupted session file detected, recreating..."
-        cat > "$RALPH_SESSION_FILE" << EOF
+        local new_session_id
-{
+        new_session_id=$(generate_session_id)
-    "session_id": "",
+
-    "created_at": "$(get_iso_timestamp)",
+        jq -n \
-    "last_used": "",
+            --arg session_id "$new_session_id" \
-    "reset_at": "",
+            --arg created_at "$ts" \
-    "reset_reason": "corrupted_file_recovery"
+            --arg last_used "$ts" \
+            --arg reset_at "$ts" \
+            --arg reset_reason "corrupted_file_recovery" \
+            '{
+                session_id: $session_id,
+                created_at: $created_at,
+                last_used: $last_used,
+                reset_at: $reset_at,
+                reset_reason: $reset_reason
+            }' > "$RALPH_SESSION_FILE"
+    fi
 }
-EOF
+
+# Update last_used timestamp in session file (called on each loop iteration)
+update_session_last_used() {
+    if [[ ! -f "$RALPH_SESSION_FILE" ]]; then
+        return 0
+    fi
+
+    local ts
+    ts=$(get_iso_timestamp)
+
+    # Update last_used in existing session file
+    local updated
+    updated=$(jq --arg last_used "$ts" '.last_used = $last_used' "$RALPH_SESSION_FILE" 2>/dev/null)
+    local jq_status=$?
+
+    if [[ $jq_status -eq 0 && -n "$updated" ]]; then
+        echo "$updated" > "$RALPH_SESSION_FILE"
     fi
 }
 
@@ -899,6 +977,10 @@ main() {
     while true; do
         loop_count=$((loop_count + 1))
         log_status "INFO" "DEBUG: Successfully incremented loop_count to $loop_count"
+
+        # Update session last_used timestamp
+        update_session_last_used
+
         log_status "INFO" "Loop #$loop_count - calling init_call_tracking..."
         init_call_tracking
         
@@ -1031,6 +1113,10 @@ Files created:
     - $LOG_DIR/: All execution logs
     - $DOCS_DIR/: Generated documentation
     - $STATUS_FILE: Current status (JSON)
+    - .ralph_session: Session lifecycle tracking
+    - .ralph_session_history: Session transition history (last 50)
+    - .call_count: API call counter for rate limiting
+    - .last_reset: Timestamp of last rate limit reset
 
 Example workflow:
     ralph-setup my-project     # Create project