feat: team-friendly gstack install mode (v0.15.7.0) (#809)

* feat: add gstack-settings-hook for atomic Claude Code hook management

DRY helper for adding/removing SessionStart hooks in ~/.claude/settings.json.
Handles missing files, deduplication, malformed JSON, and atomic writes
(.tmp + rename) to prevent corruption on crash or disk-full.

Part of team-install-mode feature (credit: Jared Friedman).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add gstack-session-update for automatic team updates

SessionStart hook target that auto-updates gstack at session start.
Background fork (zero latency), throttled to once/hour, with lockfile
(mkdir + PID), stale lock recovery, GIT_TERMINAL_PROMPT=0, and debug
logging to ~/.gstack/analytics/session-update.log.

Part of team-install-mode feature (credit: Jared Friedman).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add --team, --no-team, -q flags to setup

--team enables auto_upgrade and registers SessionStart hook via
gstack-settings-hook. --no-team reverses it. -q/--quiet suppresses
all informational output (for hook-triggered setup runs). --local
now prints a deprecation warning.

Replaces ~20 echo calls with log() helper for quiet mode support.

Part of team-install-mode feature (credit: Jared Friedman).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add gstack-team-init for repo-level team bootstrapping

Two modes: 'optional' (gentle CLAUDE.md suggestion) and 'required'
(CLAUDE.md enforcement + .claude/hooks/check-gstack.sh PreToolUse hook
that blocks work without gstack installed). Atomic JSON writes,
idempotent, prints git add instructions.

Part of team-install-mode feature (credit: Jared Friedman).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: deprecate vendoring, document team mode, clean up uninstall

- README: replace "Step 2: Add to your repo" vendoring instructions
  with team mode (./setup --team + gstack-team-init)
- CLAUDE.md: rename "Vendored symlink awareness" to "Dev symlink
  awareness", add deprecation note
- CONTRIBUTING.md: remove vendoring language from prefix section
- bin/gstack-uninstall: clean up SessionStart hook on uninstall

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add vendoring deprecation detection to skill preamble

Detects vendored gstack in CWD (.claude/skills/gstack/ that's not a
symlink and has VERSION or .git). Outputs VENDORED_GSTACK: yes/no.
Adds generateVendoringDeprecation() section that offers one-time
migration to team mode via AskUserQuestion.

Part of team-install-mode feature (credit: Jared Friedman).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: regenerate SKILL.md files with vendoring deprecation preamble

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: team mode (v0.15.7.0) — credit Jared Friedman

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test: add integration tests for team mode (20 tests)

Covers gstack-settings-hook (add, remove, dedup, preserve existing,
atomic write), gstack-session-update (guards, throttle, non-fatal),
gstack-team-init (optional, required, enforcement hook, idempotent),
and setup flags (-q, --local deprecation).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ship/SKILL.md

@@ -86,6 +86,14 @@ fi
 _ROUTING_DECLINED=$(~/.claude/skills/gstack/bin/gstack-config get routing_declined 2>/dev/null || echo "false")
 echo "HAS_ROUTING: $_HAS_ROUTING"
 echo "ROUTING_DECLINED: $_ROUTING_DECLINED"
+# Vendoring deprecation: detect if CWD has a vendored gstack copy
+_VENDORED="no"
+if [ -d ".claude/skills/gstack" ] && [ ! -L ".claude/skills/gstack" ]; then
+  if [ -f ".claude/skills/gstack/VERSION" ] || [ -d ".claude/skills/gstack/.git" ]; then
+    _VENDORED="yes"
+  fi
+fi
+echo "VENDORED_GSTACK: $_VENDORED"
 # Detect spawned session (OpenClaw or other orchestrator)
 [ -n "$OPENCLAW_SESSION" ] && echo "SPAWNED_SESSION: true" || true
 ```
@@ -214,6 +222,38 @@ Say "No problem. You can add routing rules later by running `gstack-config set r
 
 This only happens once per project. If `HAS_ROUTING` is `yes` or `ROUTING_DECLINED` is `true`, skip this entirely.
 
+If `VENDORED_GSTACK` is `yes`: This project has a vendored copy of gstack at
+`.claude/skills/gstack/`. Vendoring is deprecated. We will not keep vendored copies
+up to date, so this project's gstack will fall behind.
+
+Use AskUserQuestion (one-time per project, check for `~/.gstack/.vendoring-warned-$SLUG` marker):
+
+> This project has gstack vendored in `.claude/skills/gstack/`. Vendoring is deprecated.
+> We won't keep this copy up to date, so you'll fall behind on new features and fixes.
+>
+> Want to migrate to team mode? It takes about 30 seconds.
+
+Options:
+- A) Yes, migrate to team mode now
+- B) No, I'll handle it myself
+
+If A:
+1. Run `git rm -r .claude/skills/gstack/`
+2. Run `echo '.claude/skills/gstack/' >> .gitignore`
+3. Run `~/.claude/skills/gstack/bin/gstack-team-init required` (or `optional`)
+4. Run `git add .claude/ .gitignore CLAUDE.md && git commit -m "chore: migrate gstack from vendored to team mode"`
+5. Tell the user: "Done. Each developer now runs: `cd ~/.claude/skills/gstack && ./setup --team`"
+
+If B: say "OK, you're on your own to keep the vendored copy up to date."
+
+Always run (regardless of choice):
+```bash
+eval "$(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)" 2>/dev/null || true
+touch ~/.gstack/.vendoring-warned-${SLUG:-unknown}
+```
+
+This only happens once per project. If the marker file exists, skip entirely.
+
 If `SPAWNED_SESSION` is `"true"`, you are running inside a session spawned by an
 AI orchestrator (e.g., OpenClaw). In spawned sessions:
 - Do NOT use AskUserQuestion for interactive prompts. Auto-choose the recommended option.