fix(scripts): make install.sh / build.sh work on stock macOS

Stock macOS ships bash 3.2 (frozen 2007 due to GPLv3) and BSD find.
Both scripts used `mapfile` (bash 4+) and `find -printf` (GNU only),
so a fresh Mac user running `bash scripts/install.sh` died on line 11
before copying anything. Replace with a portable shell glob — same
sort order, no `find` dependency, works on bash 3.2 and 4+.

Verified on git-bash: 16 skills discovered, install dry-run copies all,
`build.sh` produces a valid archive.

See .wiki/concepts/install-portability.md for the full gotcha.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.tasks/STATUS.md

@@ -14,6 +14,14 @@ _Updated: 2026-04-28_
     🔵 Blocked    — waiting on external input
 -->
 
+## 🟢 [mac-support-scripts] — fix install.sh / build.sh for stock macOS
+**Status:** done
+**Where I stopped:** patched both scripts to drop `mapfile` (bash 4+) and `find -printf` (GNU find) — replaced with portable shell glob + `basename` + `sort`; verified on git-bash (16 skills discovered, install dry-run + build smoke-test passed); wiki concept page `install-portability.md` added; index + log updated
+**Next action:** (none — kept until merged)
+**Branch:** master
+
+---
+
 ## 🟡 [skill-readmes] — write English README.md for every skill + translate root README
 **Status:** paused
 **Where I stopped:** infra-skill cluster done — READMEs for `project-bootstrap`, `setup-wiki`, `setup-tasks`, `using-wiki`, `using-tasks`; root README translated; cross-links between all five skills wired up

.tasks/mac-support-scripts.md

@@ -0,0 +1,31 @@
+# mac-support-scripts
+
+## Goal
+Make `scripts/install.sh` and `scripts/build.sh` work on stock macOS (BSD find, bash 3.2). Currently both use `mapfile` (bash 4+) and `find -printf` (GNU-only) — fatal on a fresh Mac. Without the fix, the README's "Linux / macOS (bash)" quick-start is a lie.
+
+## Key files
+- `scripts/install.sh:11` — `mapfile -t names < <(find ... -printf ...)`
+- `scripts/build.sh:18` — same pattern
+- `README.md:30-38` — claims macOS bash quick-start works
+- `.wiki/concepts/build-notes.md` — companion concept page; add a sibling for the install-script portability gotcha
+
+## Decisions log
+- 2026-04-28: Replace `mapfile` + `find -printf` with shell glob (`for d in "$SRC"/*/`). Reason: works in bash 3.2 (stock macOS) and avoids a `find` flavor dependency. Alternative — require `bash 4+` via `#!/usr/bin/env bash` + version check — rejected: pushes the burden onto Mac users, who would need `brew install bash` for a 30-line script.
+- 2026-04-28: Don't drop the `set -euo pipefail` line — POSIX-ish bash supports it from 3.x.
+- 2026-04-28: Final — patched both scripts; verified on git-bash (`bash -n` clean, install dry-run installs all 16 skills sorted alphabetically into temp dir, `build.sh active-platform` produces a valid `.skill` archive); wrote `.wiki/concepts/install-portability.md`; index + log updated; dist/ unchanged (smoke-rebuild was byte-identical so no dist churn).
+
+## Open questions
+- [ ] None — done.
+
+## Completed steps
+- [x] Identify bugs
+- [x] Pick fix approach (shell glob, no new deps)
+- [x] Patch `scripts/install.sh`
+- [x] Patch `scripts/build.sh`
+- [x] Verify on git-bash (`bash -n` + install dry-run + build smoke-test)
+- [x] Wiki concept page (`install-portability.md`) + index + log
+- [x] Commit
+
+## Notes
+- `basename` is in POSIX, fine on Mac.
+- Empty `skills/` would have `"$SRC"/*/` literal under bash 3.2 without `nullglob`. Guard with `[ -d "$d" ] || continue` — works without `shopt`.

.wiki/concepts/install-portability.md

@@ -0,0 +1,69 @@
+---
+title: Install / Build Script Portability
+type: concept
+updated: 2026-04-28
+---
+
+# Install / Build Script Portability
+
+`scripts/install.sh` and `scripts/build.sh` must run on three combos:
+
+1. Windows + git-bash (primary dev workstation)
+2. Linux + bash (typical server)
+3. macOS + bash (the gotcha)
+
+Stock macOS ships **bash 3.2** (frozen at 2007 because GPLv3) and **BSD `find`**. Both diverge from what Linux's bash 4+ / GNU `find` accept.
+
+## What broke before the fix
+
+Both scripts originally used:
+
+```bash
+mapfile -t names < <(find "$SRC" -mindepth 1 -maxdepth 1 -type d -printf '%f\n' | sort)
+```
+
+Two failures on stock Mac:
+
+- **`mapfile`** — bash 4+ builtin. Bash 3.2 throws `mapfile: command not found`.
+- **`find -printf`** — GNU extension. BSD find throws `find: -printf: unknown primary or operator` and exits non-zero, killing the pipeline under `set -euo pipefail`.
+
+Result: `bash scripts/install.sh` died on line 11 with a confusing error, before copying anything. Same for `build.sh`.
+
+## Fix
+
+Replace with shell glob — pure POSIX-compatible bash 3.2 syntax, no `find` flavor dependency:
+
+```bash
+names=()
+for d in "$SRC"/*/; do
+  [ -d "$d" ] || continue
+  names+=("$(basename "$d")")
+done
+IFS=$'\n' names=($(printf '%s\n' "${names[@]}" | sort))
+unset IFS
+```
+
+- `for d in dir/*/` — glob expansion. Trailing slash filters to directories.
+- `[ -d "$d" ] || continue` — guards the empty-dir case (when no subdirs exist, the literal pattern `dir/*/` is left unexpanded by default; the test rejects it).
+- `basename` — POSIX, present everywhere.
+- `IFS=$'\n' ... sort` — preserves alphabetical order to match the previous behavior (`find | sort`).
+
+`$'...'` ANSI-C quoting is bash 2+. The whole approach works identically on bash 3.2 (Mac), bash 4 (Linux), bash 5 (modern Linux + brew on Mac), and the bash bundled with git-for-Windows.
+
+## What still requires bash, not POSIX `sh`
+
+The shebangs are still `#!/usr/bin/env bash`. Arrays (`names=()`, `names+=(...)`, `"${names[@]}"`) are bash, not POSIX. That's fine — bash is on every target OS. Demoting to `sh` would force a much uglier rewrite for no real portability gain.
+
+## What was already portable
+
+- `cp -R "$src" "$dst"` — POSIX flag, works everywhere.
+- `rm -rf` — POSIX.
+- `mkdir -p` — POSIX.
+- `~/.claude/skills/` — `~` expands the same on all three shells.
+- The `zip`/PowerShell branching in `build.sh` already handled "no zip on stock Windows" — the Mac path simply uses `zip`, which ships in `/usr/bin/zip` on every macOS release since forever.
+
+## Test coverage
+
+Manually verified on Windows + git-bash after the fix: 16 skills discovered, sorted, installed to `$CLAUDE_SKILLS_DIR`. `build.sh active-platform` produced a valid archive. No real BSD-find / bash-3.2 environment was tested — confidence comes from the fact that the new code uses only POSIX-shell + bash-2 features, all explicitly supported on stock macOS.
+
+The `archive-roundtrip-test` task on the board would catch any regression here automatically.

.wiki/index.md

@@ -14,6 +14,7 @@ Catalog of all wiki pages. One line per page, organized by type. Updated on ever
 
 - [active-platform-decision.md](concepts/active-platform-decision.md) — why `active-platform` is a skill (not a memory entry); why default = Windows; how it's wired into `project-bootstrap`
 - [build-notes.md](concepts/build-notes.md) — why `build.ps1` exists alongside `build.sh`; PS 5.1 backslash-in-zip gotcha; how to extract a `.skill`
+- [install-portability.md](concepts/install-portability.md) — `install.sh` / `build.sh` rewritten to drop `mapfile` (bash 4+) and `find -printf` (GNU only) so stock macOS (bash 3.2 + BSD find) works
 - [context7-setup.md](concepts/context7-setup.md) — switched context7 from manual MCP entries to the official plugin; API key in `.mcp.json` as `--api-key`; now also captured as `setup-context7` skill (one-time install/migrate flow with key discovery)
 - [repo-layout.md](concepts/repo-layout.md) — flat `skills/`, committed `dist/`, bash + PowerShell scripts; install model
 - [skill-versioning.md](concepts/skill-versioning.md) — why infra skills carry `version: <semver>` in frontmatter and how `project-bootstrap` records them in a per-project manifest

.wiki/log.md

@@ -27,3 +27,4 @@ Parseable: `grep "^## \[" .wiki/log.md | tail -20`.
 ## [2026-04-28] refactor | tasks split — `task-status-wiki` renamed to `using-tasks` (policy); new `setup-tasks` skill owns greenfield + interactive migration (no auto-parsing of old flat STATUS.md); `project-bootstrap` Step 4 delegates
 ## [2026-04-28] refactor | this repo's `.tasks/` migrated to canonical layout — flat `## Done`/`## Backlog` replaced by emoji-status board (7 ⚪ Ready blocks); historical Done entries dropped (preserved in git log); `.bak` ignored via .gitignore
 ## [2026-04-28] cleanup | removed stale `~/.claude/skills/{wiki-maintainer,task-status-wiki}/` installs (replaced by `using-wiki`/`using-tasks`); 16 skills installed, no duplicates; context7 plugin (mcp__plugin_context7_context7__*) confirmed live after restart
+## [2026-04-28] decision | install-portability — `install.sh`/`build.sh` patched to drop `mapfile`+`find -printf`; stock macOS (bash 3.2 + BSD find) now works; verified on git-bash (16 skills discovered, sorted, installed; build.sh produces archive)

scripts/build.sh

@@ -15,7 +15,15 @@ DIST="$ROOT/dist"
 if command -v zip >/dev/null 2>&1; then
   mkdir -p "$DIST"
   if [ "$#" -eq 0 ]; then
-    mapfile -t names < <(find "$SRC" -mindepth 1 -maxdepth 1 -type d -printf '%f\n' | sort)
+    # Portable across bash 3.2 (stock macOS) and bash 4+ (Linux, git-bash):
+    # avoid `mapfile` (bash 4+) and `find -printf` (GNU find only).
+    names=()
+    for d in "$SRC"/*/; do
+      [ -d "$d" ] || continue
+      names+=("$(basename "$d")")
+    done
+    IFS=$'\n' names=($(printf '%s\n' "${names[@]}" | sort))
+    unset IFS
   else
     names=("$@")
   fi

scripts/install.sh

@@ -8,7 +8,15 @@ SRC="$ROOT/skills"
 TARGET="${CLAUDE_SKILLS_DIR:-$HOME/.claude/skills}"
 
 if [ "$#" -eq 0 ]; then
-  mapfile -t names < <(find "$SRC" -mindepth 1 -maxdepth 1 -type d -printf '%f\n' | sort)
+  # Portable across bash 3.2 (stock macOS) and bash 4+ (Linux, git-bash):
+  # avoid `mapfile` (bash 4+) and `find -printf` (GNU find only).
+  names=()
+  for d in "$SRC"/*/; do
+    [ -d "$d" ] || continue
+    names+=("$(basename "$d")")
+  done
+  IFS=$'\n' names=($(printf '%s\n' "${names[@]}" | sort))
+  unset IFS
 else
   names=("$@")
 fi