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>

scripts/resolvers/preamble.ts

@@ -89,6 +89,14 @@ fi
 _ROUTING_DECLINED=$(${ctx.paths.binDir}/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
 \`\`\``;
@@ -228,6 +236,40 @@ Say "No problem. You can add routing rules later by running \`gstack-config set
 This only happens once per project. If \`HAS_ROUTING\` is \`yes\` or \`ROUTING_DECLINED\` is \`true\`, skip this entirely.`;
 }
 
+function generateVendoringDeprecation(ctx: TemplateContext): string {
+  return `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-$SLUG\` marker):
+
+> This project has gstack vendored in \`.claude/skills/gstack/\`. Vendoring is deprecated.
+> We won't keep this copy up to date, so you'll fall behind on new features and fixes.
+>
+> Want to migrate to team mode? It takes about 30 seconds.
+
+Options:
+- A) Yes, migrate to team mode now
+- B) No, I'll handle it myself
+
+If A:
+1. Run \`git rm -r .claude/skills/gstack/\`
+2. Run \`echo '.claude/skills/gstack/' >> .gitignore\`
+3. Run \`${ctx.paths.binDir}/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 "$(${ctx.paths.binDir}/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.`;
+}
+
 function generateSpawnedSessionCheck(): string {
   return `If \`SPAWNED_SESSION\` is \`"true"\`, you are running inside a session spawned by an
 AI orchestrator (e.g., OpenClaw). In spawned sessions:
@@ -686,6 +728,7 @@ export function generatePreamble(ctx: TemplateContext): string {
     generateTelemetryPrompt(ctx),
     generateProactivePrompt(ctx),
     generateRoutingInjection(ctx),
+    generateVendoringDeprecation(ctx),
     generateSpawnedSessionCheck(),
     generateVoiceDirective(tier),
     ...(tier >= 2 ? [generateContextRecovery(ctx), generateAskUserFormat(ctx), generateCompletenessSection()] : []),