fix: harden CLI per code review; require Bash 4+

[d6veteran]

Summary

Two commits: (1) fixes every High/Medium/Low finding from Robin's code-quality review of the shell codebase, and (2) raises the supported shell floor from Bash 3.2 to Bash 4+, dropping stock-macOS /bin/bash support.

No user-visible behavior changes except the fixed defects: a golden comparison of the old and new CLI produced byte-identical output across list, show, use, switch, status, coordinator on/prod/off, reset, launch --dry-run, help, and the full branch lifecycle.

Review fixes (commit 1)

High severity

• Non-atomic CLAUDE.md writes (cmd_reset, coordinator off): the second filter stage redirected a pipeline straight onto ~/.claude/CLAUDE.md with || true, so an interrupt or full disk could truncate the user's global config. All block edits now go through block_install/block_remove helpers that write to a temp file and land with mv.
• Branch-index lookups compiled names as regexes: five awk sites matched $3 ~ " " proj " ". Names like release/1.2.3 cross-matched similar rows, and unbalanced metacharacters crashed awk. All five now trim fields and compare with literal string equality via one index_active_field helper.

Medium severity

• Triplicated marker-block logic: now single-sourced in the CLI helpers; install.sh delegates its coordinator step to claude-team coordinator on|prod, exercising the tested code path.
• shellcheck configured but never enforced: added .github/workflows/ci.yml (shellcheck on all five scripts + tests on ubuntu and macOS). All five scripts pass shellcheck 0.9.0 clean.

Low severity

• Block removal trims only the blank lines the removed block leaves at EOF (the old code stripped leading blanks and every line's trailing whitespace, mangling user content).
• Dead cyan() deleted; unused SC1090 suppression removed.
• Name — Role title parsing factored into first-em-dash-splitting helpers, mirrored in generate-agents.sh; regenerating all 16 agents produces a zero diff.
• session list is one awk pass instead of three subshells per line.
• Test-suite portability: POSIX ERE alternation, glob count instead of parsing ls, herestrings in assert helpers, quoted literal done.

Bash 4+ floor (commit 2)

Bash 3.2 is a 2006 release Apple froze at /bin/bash over GPLv3. Supporting it constrained the codebase for a twenty-year-old shell, so:

• README badge and Requirements now state Bash 4+, with the brew install bash note for macOS.
• bin/claude-team, install.sh, and tests/run.sh fail fast under older bash with a clear error and the brew hint, instead of misbehaving silently on stock macOS.
• The macOS CI job installs Homebrew bash and runs the suite under it; the version guard makes the job self-verifying.
• First use of the raised floor: lowercase()/capitalize() are ${var,,}/${var^} parameter expansions instead of tr/awk subshells.

Regression testing (103 → 123 assertions)

• use+reset and coordinator on+off round-trip a fixture CLAUDE.md byte-for-byte.
• Dotted and parenthesized project/branch names (my.app vs myXapp, release/1.2.3, app(1), feat/(v1.2.3)) register, resolve, and close without cross-matching or crashing, through both branch and session paths.
• A multi-dash profile title keeps its full role in list.
• install.sh runs end to end into an isolated HOME for both the "skip coordinator" and "prod" answers.
• Each new test family was executed against the previous implementation and fails there; the Bash guard was verified by flipping its threshold and observing the failure path.

bash tests/run.sh: 123/123 passing. shellcheck on all five scripts: clean.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Nx3U4ZrUAmCpsCeSxvzRWX