fix(install): tell users which folder to open their chat app in

[davekilleen]

What

One extra step in the installer's closing output:

Next steps:
  1. Open Claude Code in this folder
     (the folder you just installed into — not somewhere else)
  2. In Claude Code chat, type: /setup
  3. Answer the setup questions (~5 minutes)
  4. Start using Dex!

App detection (Claude Code / Cursor / your AI app) is unchanged — that landed in b45c3755.

Why

The documented install path is a Terminal one-liner:

curl -fsSL https://heydex.ai/install.sh | bash

So this text is read by someone sitting in a terminal with no chat app open. main currently says "In Claude Code chat, type: /setup" without saying where to open Claude Code, and opening it somewhere other than the freshly installed folder is the mistake people actually make — the chat then can't see any of Dex's files.

What this deliberately does not say

An earlier draft told users to "start a new chat" because "a new chat loads Dex's MCP servers". That was dropped: /setup works fine in an already-open session, so it added a step most people don't need and gave a reason that isn't the real one. This PR only tells them where, not to restart anything.

Tests

core/tests/test_install_convergence.py — 7 passed (5 existing, 2 new).

The fixture gains an optional chat_app shim so the detected-app path is exercisable at all, which it wasn't before. Both new tests also assert detection names one app only and never leaks the other.

Notes

• Supersedes fix(install): point users at the folder, not a new chat #421, which conflicted with main because it carried a parallel implementation of app detection already merged as b45c3755. This branch is built directly on main and touches only the closing output.
• No CHANGELOG entry — per house rules, versioning happens at release time via /dex-push.

[github-actions]

What this pull request touches

• tests — feeds catching regressions before contributors and users encounter them.

Gates that will judge this change

• Personal-data gate: added lines must not expose real identities or personal vault content.
• Change-aware gates: source changes are checked for tests, path-contract use, documentation drift, and touched-file coverage.
• Tests and coverage: the Python, MCP, migration, hook, and script suites must remain healthy.
• Safety and quality: security, lint, distribution, path consistency, and large-vault checks still apply.

Based on 2 changed files.