setup-statusline

Add the frugal savings badge to the user's statusline. The badge comes from scripts/statusline.py in this plugin, which prints frugal $<session>/$<lifetime> saved (or nothing when no metrics exist yet).

Steps

1. Locate the segment script. Find the installed copy:

   ls -d ~/.claude/plugins/cache/*/frugal/*/scripts/statusline.py 2>/dev/null | head -1

   Use the resulting absolute glob pattern ($HOME/.claude/plugins/cache/<marketplace>/frugal/*/scripts/statusline.py with a literal * for the version directory, resolved via ls ... | head -1 at runtime) so plugin updates keep working.

2. Read ~/.claude/settings.json and check the statusLine field. Three cases:

   a. Already references statusline.py from this plugin (in the command itself or inside the script the command runs): report that it is already configured and stop.

   b. No statusLine configured: create ~/.claude/frugal-statusline.sh with the content below, make it executable, and set "statusLine": {"type": "command", "command": "bash \"$HOME/.claude/frugal-statusline.sh\""} in settings.json (ask the user before writing settings.json).

   #!/bin/bash
   # Minimal statusline: model + cwd + frugal savings badge
   INPUT=$(cat)
   MODEL=$(echo "$INPUT" | jq -r '.model.display_name // empty' 2>/dev/null)
   DIR=$(basename "$(echo "$INPUT" | jq -r '.cwd // "~"' 2>/dev/null)")
   SESSION_ID=$(echo "$INPUT" | jq -r '.session_id // empty' 2>/dev/null)
   FRUGAL=""
   FRUGAL_SCRIPT=$(ls -d "$HOME"/.claude/plugins/cache/*/frugal/*/scripts/statusline.py 2>/dev/null | head -1)
   if [ -n "$FRUGAL_SCRIPT" ]; then
     TXT=$(python3 "$FRUGAL_SCRIPT" ${SESSION_ID:+--session "$SESSION_ID"} 2>/dev/null)
     [ -n "$TXT" ] && FRUGAL=" \033[38;5;114m[${TXT}]\033[0m"
   fi
   printf '%b\n' "[${MODEL:-claude}] [${DIR}]${FRUGAL}"

   c. An existing statusline is configured: read the script or command it points at, then merge the segment into it. Preferred merge: compute the badge early and append it to the script's assembled output, following this shape:

   FRUGAL=""
   FRUGAL_SCRIPT=$(ls -d "$HOME"/.claude/plugins/cache/*/frugal/*/scripts/statusline.py 2>/dev/null | head -1)
   if [ -n "$FRUGAL_SCRIPT" ]; then
     SESSION_ID=$(echo "$INPUT" | jq -r '.session_id // empty' 2>/dev/null)
     TXT=$(python3 "$FRUGAL_SCRIPT" ${SESSION_ID:+--session "$SESSION_ID"} 2>/dev/null)
     [ -n "$TXT" ] && FRUGAL="\033[38;5;114m[${TXT}]\033[0m"
   fi

   Adapt to the script's own conventions (variable names, how it reads stdin, how it assembles the final line). If the statusline is an inline command rather than a script, wrap it: create ~/.claude/frugal-statusline.sh that pipes $INPUT to the original command and appends the badge to its output, then point statusLine.command at the wrapper. Show the user the proposed edit and get consent before modifying their statusline or settings.json.

3. Verify. Pipe a fake payload through the final statusline command and confirm it exits 0 and renders (badge may be absent if no metrics exist yet - that is correct behaviour, not a failure):

   echo '{"session_id":"test","cwd":"'$HOME'","model":{"display_name":"test"}}' | <statusline command>

4. Tell the user the badge appears after the first frugal worker runs (metrics land in ~/.claude/frugal/metrics.jsonl), and that the statusline refreshes on its own.

Notes: never delete or rewrite unrelated parts of an existing statusline; make the smallest edit that adds the badge. jq and python3 are required; if missing, say so instead of installing anything.