* chore(io): migrate pkg/cache to Medium abstraction
- Added `medium io.Medium` field to `Cache` struct in `pkg/cache/cache.go`.
- Updated `cache.New` constructor to accept `io.Medium` as the first parameter, defaulting to `io.Local` if `nil`.
- Migrated all file operations in `pkg/cache` to use the `medium` abstraction.
- Replaced `os.IsNotExist` with `errors.Is(err, fs.ErrNotExist) || os.IsNotExist(err)` for better compatibility.
- Updated caller in `internal/cmd/pkgcmd/cmd_search.go`.
- Added unit tests in `pkg/cache/cache_test.go` using `io.MockMedium`.
Parent: #101
* chore(io): migrate pkg/cache to Medium abstraction
- Added `medium io.Medium` field to `Cache` struct in `pkg/cache/cache.go`.
- Updated `cache.New` constructor to accept `io.Medium` as the first parameter, defaulting to `io.Local` if `nil`.
- Migrated all file operations in `pkg/cache` to use the `medium` abstraction.
- Replaced `os.IsNotExist` with `errors.Is(err, fs.ErrNotExist) || os.IsNotExist(err)` for better compatibility.
- Updated caller in `internal/cmd/pkgcmd/cmd_search.go`.
- Added unit tests in `pkg/cache/cache_test.go` using `io.MockMedium`.
Note: CI failure 'org-gate' is a policy-level check for external contributors and does not indicate a code error. Verified with local build and tests.
* chore(io): migrate pkg/cache to Medium abstraction
- Added `medium io.Medium` field to `Cache` struct in `pkg/cache/cache.go`.
- Updated `cache.New` constructor to accept `io.Medium` as the first parameter, defaulting to `io.Local` if `nil`.
- Migrated all file operations in `pkg/cache` to use the `medium` abstraction.
- Replaced `os.IsNotExist` with `errors.Is(err, fs.ErrNotExist) || os.IsNotExist(err)` for better compatibility.
- Updated caller in `internal/cmd/pkgcmd/cmd_search.go`.
- Added unit tests in `pkg/cache/cache_test.go` using `io.MockMedium`.
Note: CI failure 'org-gate' is a policy-level check for external contributors and does not indicate a code error. Verified with local build and tests.
* chore(io): migrate pkg/cache to Medium abstraction
- Added `medium io.Medium` field to `Cache` struct in `pkg/cache/cache.go`.
- Updated `cache.New` constructor to accept `io.Medium` as the first parameter, defaulting to `io.Local` if `nil`.
- Migrated all file operations in `pkg/cache` to use the `medium` abstraction.
- Updated caller in `internal/cmd/pkgcmd/cmd_search.go`.
- Added unit tests in `pkg/cache/cache_test.go` using `io.MockMedium`, with explicit error handling as requested in PR review.
Parent: #101
