Add directory-local config and wildcard TERMINUS_USER matching

[georgestephanis]

Summary

This PR adds two small quality-of-life features for users who work with multiple Pantheon accounts (e.g. agency developers juggling client accounts).

1. Directory-local .terminus config files

A new DirectoryConfig class walks up from the current working directory to the filesystem root, looking for a .terminus YAML file. If one is found, it is loaded into the config chain between ~/.terminus/config.yml and the existing .env / environment-variable layers.

This lets you drop a .terminus file in any project root:

TERMINUS_USER: george@client-account.com
TERMINUS_ORG: client-org-name

Any terminus command run from that directory or any of its subdirectories will automatically pick up those settings — no flags or environment variables required.

Config precedence (lowest → highest):
constants.yml → ~/.terminus/config.yml → .terminus (walk-up) → .env → environment variables

2. Wildcard/partial matching for TERMINUS_USER

Authorizer::ensureLogin() now supports fnmatch-style patterns in TERMINUS_USER, so a shared .terminus file can target the right account without hardcoding a specific email:

# Match any saved token whose email is at this domain
TERMINUS_USER: "@client-domain.com"

Supported forms:

Value	Behaviour
george@example.com	Exact match (existing behaviour, unchanged)
@example.com	Matches any saved token at that domain (normalized to *@example.com)
*@example.com	Same, explicit form
george@*	Matches any domain for that username

If the pattern matches zero tokens, a clear error directs the user to auth:login. If it matches more than one, an error asks them to be more specific — useful when a team member has tokens for multiple accounts at the same domain.

The TERMINUS_USER check is now evaluated before the single-token auto-select, so an explicit pattern always takes priority.

Changed files

• src/Config/DirectoryConfig.php (new) — walks up directory tree to find and load .terminus
• src/Terminus.php — inserts DirectoryConfig into the factory() config chain
• src/Hooks/Authorizer.php — adds isEmailPattern() and matchTokenByPattern() helpers

Testing

All existing unit tests pass. Because both features interact with the filesystem and the saved-token store rather than the Pantheon API, they are best exercised manually or via future functional tests:

# Verify directory config is picked up
mkdir /tmp/terminus-test && echo "TERMINUS_USER: you@example.com" > /tmp/terminus-test/.terminus
cd /tmp/terminus-test && terminus auth:whoami

# Verify walk-up from a subdirectory
mkdir /tmp/terminus-test/sub && cd /tmp/terminus-test/sub && terminus auth:whoami

# Verify wildcard matching (with two tokens saved at the same domain)
echo "TERMINUS_USER: '@example.com'" > /tmp/terminus-test/.terminus
cd /tmp/terminus-test && terminus auth:whoami

---

AI assistance disclosure: The design and implementation of this PR were driven by George Stephanis. Code was written with the assistance of Claude Code (Anthropic), using the Claude Sonnet 4.6 model (claude-sonnet-4-6). The iterative design conversation — including a deliberate simplification pass that removed an over-engineered "named profiles" system in favour of the lighter approach here — was conducted interactively with a human in the loop at every decision point.