Fix test isolation to prevent config file modifications

[JAORMX]

Problem:
Tests were modifying the real configuration file at ~/.config/toolhive/config.yaml
because they were using the global singleton config pattern, which automatically
loads and saves to the default XDG config path.

Root Cause:

1. The singleton pattern in pkg/config was being triggered by tests
2. LoadOrCreateConfigWithPath had a critical bug where it called config.save()
   instead of config.saveToPath(configPath), causing even tests with temp
   directories to save to the real config location
3. Tests were directly calling config.GetConfig() which triggers singleton
   initialization with the real config file

Solution:

1. Introduced dependency injection with config.Provider interface
   • DefaultProvider: Uses the singleton (for production)
   • PathProvider: Uses a specific path (for tests)
2. Fixed the critical bug in LoadOrCreateConfigWithPath (line 179)
   • Changed from config.save() to config.saveToPath(configPath)
3. Updated all components to accept config providers:
   • API routes (registry, secrets)
   • Client manager
   • Workloads manager
   • Registry factory
   • Runner components
   • Migration utilities
4. Modified all tests to use CreateTestConfigProvider() helper
   • Creates temporary directories for test isolation
   • Uses PathProvider to avoid singleton initialization
5. Fixed race conditions in parallel tests by ensuring each
   subtest has its own mock controller

Impact:

• Tests no longer modify the real config file
• Each test runs in complete isolation with its own config
• Parallel test execution is now safe
• Production code continues to use the singleton pattern
• Backward compatibility maintained for existing code

Verified:
All 56 test functions in pkg/api/v1 and pkg/registry now pass
without modifying ~/.config/toolhive/config.yaml

Signed-off-by: Juan Antonio Osorio [email protected]