[bug] Extension Download Test Failures on darwin_arm64

Extension Download Test Failures on darwin_arm64

Description

The extension download functionality tests are failing when running make test on macOS with ARM64 architecture. The tests fail to find architecture-specific binaries in the mock Docker registry.

Error Details

=== FAIL: TestExtensionCmd/normal (0.01s)
Error: not found atest-store-git_darwin_arm64/atest-store-git from http://127.0.0.1:55323/v2/linuxsuren/atest-ext-store-git/manifests/0.0.2
Error: not found atest-store-orm_darwin_arm64/atest-store-orm from http://127.0.0.1:55323/v2/linuxsuren/atest-ext-store-orm/manifests/0.0.2

Environment

• OS: macOS (Darwin 25.0.0)
• Architecture: ARM64 (Apple Silicon)
• Test: TestExtensionCmd in cmd/extension_test.go
• Mock Registry: 127.0.0.1:55323

Root Cause Analysis

1. Architecture-Specific Binary Missing: The test expects darwin_arm64 binaries but the mock Docker registry only contains limited test data
2. Mock Registry Incomplete: The simulated registry manifests don't include all required architecture variants
3. Platform Detection: The extension system correctly detects darwin_arm64 but can't find matching binaries

Impact

• Extension installation tests fail on ARM64 macOS systems
• Core API testing functionality remains unaffected
• CI/CD might fail on ARM64 runners

Reproduction Steps

1. Run make test on macOS with ARM64 architecture
2. Observe TestExtensionCmd/normal test failure
3. Check mock registry logs for missing manifest requests

Suggested Solutions

1. Expand Mock Registry Data: Add darwin_arm64 binaries to test fixtures
2. Platform Fallback Logic: Implement fallback to linux_amd64 for testing
3. Skip Architecture-Specific Tests: Skip extension tests on unsupported platforms
4. Mock Registry Enhancement: Generate complete manifest data for all supported architectures

Files Involved

• cmd/extension_test.go:66 - Test assertion location
• Mock registry configuration and test data
• Extension download and platform detection logic

Priority

Low - This affects testing infrastructure but not core functionality. Extension system works in production environments with proper registries.

Start with cmd/extension_test.go:66 and run TestExtensionCmd, or reproduce with make test on darwin_arm64. Then inspect the mock registry configuration and test data for the missing architecture-specific binaries and compare the requested manifests. Done means the extension download tests pass on ARM64 macOS without affecting the existing test behavior.