fix(claude-code): remove disabled managed configuration

[Edd88-pixel]

Why

Setting managed_settings or api_key_helper to null currently leaves the module-generated files behind, so persistent workspaces keep using configuration that was removed from the template.

Changes

• Remove only the disabled module's policy file or API key helper files, preserving unrelated configuration and any policy still needed for gateway authentication.
• Report cleanup failures and cover repeated runs, independent and simultaneous disabling, permissions, and symlinks with regression tests.
• Document the cleanup behavior and bump the module to 5.5.2.

Type of Change

• Bug fix

Module Information

Path: registry/coder/modules/claude-code
New version: 5.5.2
Breaking change: No

Validation

• bun test main.test.ts from the module directory: 38 passed, 0 failed in Docker. The three disable-transition tests fail against the previous installer.
• terraform test -no-color from the module directory: 46 passed, 0 failed.

Related Issues

Closes #1156.

REG-123