[marcleblanc2]

Description

On Apple Silicon without Rosetta 2, four test suites fail on master:

bin/terraform: line 32: .../versions/0.12.1/terraform: Bad CPU type in executable

HashiCorp shipped no darwin_arm64 builds before Terraform 1.0.2, so tfenv-install correctly falls back to darwin_amd64 for those versions (see #437, #372). The binary installs, but check_installed_version / check_active_version cannot execute it without Rosetta. install_and_use, prerelease_filter, use_dash and use_latestallowed all exercise pre-1.0.2 versions, so AGENTS.md's "run the test suite locally and verify all tests pass" is impossible on such a machine.

This PR makes the suite Rosetta-aware without losing coverage anywhere Rosetta is present:

• test_common.sh: can_run_pre_1_0_2_terraform() returns false only on Darwin arm64 where arch -x86_64 /usr/bin/true fails. Linux, Windows, Intel macOS and Apple Silicon with Rosetta are unaffected.
• Cases that exist specifically to exercise 0.x ranges (latest:^0.14., latest:^0.11., 0.11.15-oci, <=0.13.0-rc1, ~> 0.12) are skipped with a warn log when it returns false, following the existing "We're Darwin! Skipping legacy tests" pattern.
• Cases that only used an old version incidentally now use 1.x so they run everywhere: tfenv use - (0.12.1/0.12.2 → 1.6.0/1.6.1), v prefix (v0.14.6 → v1.5.7), -chdir auto-install (~> 0.14.3 → ~> 1.6.3, resolving to 1.6.6).

No change to lib/, libexec/ or bin/.

Issue Link

Fixes #543

Related: #437, #372 (maintainer confirmed Rosetta 2 is the supported path for pre-1.0.2 on Apple Silicon)

Testing

• Ran ./test/run.sh locally; all suites pass. The four affected suites now log a skip for the pre-1.0.2 cases and pass the rest, where on master they fail with Bad CPU type in executable.
• Tested on at least one platform (note which below)
• This branch passes on macos-latest (arm64, Rosetta 2 present) and ubuntu-latest with this repo's unchanged test.yml run on a fork (run 41151236326): all 15 suites pass, and on macOS the pre-1.0.2 cases run rather than skip, so CI coverage is unchanged. Note: fork PR runs on this repo currently die before any job starts ("workflow file issue"), so the checks here have not executed.
• New tests added: none; existing cases reorganised

Platform tested: macOS 26 (arm64), no Rosetta 2 installed

Quality Checklist

• Shell quoting verified — all variables quoted, braces used
• Cross-platform considered — BSD vs GNU tool differences (arch is macOS-only and only reached on Darwin)
• No unintended changes to other commands
• README.md updated (not user-facing)
• CHANGELOG.md updated (test-only change)