feat(coding-agent): isolate SproutClaw namespace from upstream pi

Use piConfig name sproutclaw and configDir .sproutclaw so commands, env vars,
and project config no longer collide with the stock pi install.

Co-authored-by: Cursor <cursoragent@cursor.com>

test.sh

@@ -5,7 +5,7 @@ SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 # Default to the repository-local pi config so this source checkout uses the
 # copied learning config instead of ~/.pi.
-export PI_CODING_AGENT_DIR="${PI_CODING_AGENT_DIR:-$SCRIPT_DIR/.pi/agent}"
+export SPROUTCLAW_CODING_AGENT_DIR="${SPROUTCLAW_CODING_AGENT_DIR:-$SCRIPT_DIR/.sproutclaw/agent}"
 
 # Check for --no-env flag
 NO_ENV=false