fix(setup): anchor config paths to script directory

[0xghost42]

Summary

Closes #86.

just setup fails with

✗ No profiles found in config/profiles
error: Recipe `setup` failed on line 73 with exit code 1

on a clean checkout where config/profiles/*.yaml clearly exists.

Root cause

CONFIG_DIR was set as the relative string "config", and PROFILES_DIR=\"$CONFIG_DIR/profiles\" captures that string (not a resolved path) at script load time.

The top of the script does cd \"$SCRIPT_DIR\" once, but later setup steps cd around — notably install_optional_tools cd's into temporary directories while installing goofys / e2b (lines 540–572). If any of those install attempts leaves the working directory drifted before select_profile runs, the relative \"config/profiles\"/*.yaml glob expands against the wrong directory and discover_profiles returns an empty array.

This is consistent with the trace in #86 where the failure lands right after the optional-tools step.

Change

setup.sh:

• Anchor CONFIG_DIR to \"$SCRIPT_DIR/config\". Every downstream path (PROFILES_DIR, EXAMPLES_DIR, DEFAULTS_DIR) becomes an absolute path, immune to cwd drift between functions.
• Add a second line to the "No profiles found" error that prints the current working directory, so any future occurrence is one error message away from being diagnosable instead of needing a reproducer.

Verification

• bash -n setup.sh clean.
• The existing top-of-file cd \"$SCRIPT_DIR\" is retained; this PR is purely defensive against cwd drift in helper functions further down.
• No other path in the script depends on CONFIG_DIR being relative.