install script ignores PI_CODING_AGENT_DIR (hardcodes ~/.pi/agent)

[anntnzrb]

Summary

The installer hardcodes ~/.pi/agent and ignores PI_CODING_AGENT_DIR, so on setups using a custom agent dir (e.g. ~/.config/pi/agent) the extension/skill are copied to the wrong location.

Environment

• pi version: 0.50.3
• OS: macOS
• PI_CODING_AGENT_DIR: set to a non-default path
• Package: pi-interactive-shell 0.6.2

Steps to Reproduce

1. Set PI_CODING_AGENT_DIR to a non-default path (e.g. ~/.config/pi/agent).
2. Run pi install npm:pi-interactive-shell.
3. Inspect the configured agent dir’s extensions/ and skills/.

Actual

Installer copies to ~/.pi/agent/extensions/interactive-shell and creates a skill symlink under ~/.pi/agent/skills/interactive-shell. No files are placed under $PI_CODING_AGENT_DIR.

Expected

Installer should respect PI_CODING_AGENT_DIR (or equivalent) so extension/skill land under the configured Pi agent dir.

Root Cause

scripts/install.js uses:

const EXTENSION_DIR = join(homedir(), ".pi", "agent", "extensions", "interactive-shell");
const SKILL_DIR = join(homedir(), ".pi", "agent", "skills", "interactive-shell");

No lookup of PI_CODING_AGENT_DIR.

Workaround

Manually copy the package into $PI_CODING_AGENT_DIR/extensions/interactive-shell and copy SKILL.md into $PI_CODING_AGENT_DIR/skills/interactive-shell.

Suggested Fix

Read PI_CODING_AGENT_DIR (and expand ~) when constructing destination paths, falling back to ~/.pi/agent if unset.

[anntnzrb]

Additional related issue: the extension’s config loader also hardcodes ~/.pi/agent and doesn’t respect PI_CODING_AGENT_DIR.

In config.ts:

const projectPath = join(cwd, ".pi", "interactive-shell.json");
const globalPath = join(homedir(), ".pi", "agent", "interactive-shell.json");

So users with a non-default agent dir can’t place global config in their configured location. This seems like a separate bug from the installer, but same root cause (hardcoded agent dir).