Updates the `Taskfile.yml` to include the `tdd/` directory's tests in the coverage calculation for the `pkg/` directory by using the `-coverpkg` flag. This ensures that the coverage reports accurately reflect the state of the codebase.
Also, this commit includes the necessary environment configuration to fix a known issue in Go 1.25 that caused the `go: no such tool "covdata"` error.
This commit restructures the `crypt` service to be more modular and decoupled from storage concerns.
- The standard cryptographic implementations (`lthn`, `chachapoly`, `rsa`) have been moved to the `pkg/crypt/std` directory.
- The `rootfs` components have been removed to decouple the library from storage.
- Import paths have been updated to reflect the new structure.