* fix(scripts): use system Bash for macOS tooling and owned Mach-O fixtures
Pin native entrypoints and package commands to /bin/bash, guard portable heredoc callers on Darwin, and preserve Bash 3.2 boolean parsing. Streamed installers explain how to use system Bash when their input cannot be replayed.
Generate deterministic x86_64, arm64, and arm64e framework fixtures instead of borrowing /bin/ls. Preserve the existing framework pipeline repair from #141056 and verify merged slice bytes.
* fix(scripts): keep guarded portable scripts bash 3.2 compatible
* fix(scripts): keep macOS Bash CI coverage green
Distinguish sourced installer returns from stdin exits without ShellCheck unreachable-code warnings. Retain the shebang regression suite in changed-target routing, and repartition hosted tooling tails toward 50-second groups within the existing 150-second budget and 80-job cap.
Validation: 635 interpreter and routing tests plus 53 planner tests passed; ShellCheck, targeted lint, formatting, and fresh Codex review passed. The broader local changed-file check hit an unrelated existing dependency graph crossing through extensions/reef/node_modules/@noble/hashes; exact-head hosted CI remains required.
* docs(install): use system Bash in install and recovery commands
Align macOS-facing copy-and-paste commands and emitted installer guidance with the supported streamed interpreter. This addresses the remaining installer-command review finding without changing the PR body.
Validation: streamed help for both installers, install.sh dry-run, 16 selected fresh-install and upgrade lifecycle tests, formatting, diff check, and fresh Codex review passed. Landing remains blocked by unrelated provider-transport integration CI failure caused by an unchanged incomplete plugin-registry mock.
* fix(scripts): preserve streamed installs and CI packing
Keep public installer commands portable while replaying Darwin Bash 5.3+
stdin under system Bash through an immediately unlinked private temp file.
Retain actionable sourced-install rejection and the SC2317-safe check.
Restore the original CI packing policy and move the Bash policy scan into
its existing macOS tooling owner without adding a routed test file.
Validation: real Homebrew Bash streamed help and cleanup; 642 scan/routing
tests; 23 selected installer tests under both PATH orders; planner cap and
coverage tests; 139 Bash syntax checks; ShellCheck; 1,135 changed-gate tests;
focused lint/changed-check repair; fresh Codex review with no P0/P1 findings.
