chore(config): centralize git for teammates and enable tmux panes

Two agent-team tooling changes:

- teammateMode: in-process -> auto. Teammates now spawn in tmux split panes
  when the lead runs inside tmux, with graceful in-process fallback.
- New PreToolUse hook git-centralize-guard.sh blocks .git-mutating commands
  (add, commit, merge, push, pull, rebase, reset, checkout, stash,
  cherry-pick, rm, mv) for teammates, keeping version control centralized to
  the lead. Detection keys on the agent_type field, which a teammate's hook
  input carries and the lead's does not. Read-only git is allowed.

Documented in .claude/rules/git-safety.md. Hooks load at lead startup, so a
restart is required for the hook to reach teammates.

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

.claude/hooks/git-centralize-guard.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# git-centralize-guard: PreToolUse hook that blocks .git-mutating commands for
+# agent-team teammates. Version control is centralized to the team lead
+# (see CLAUDE.md / memory: "Team lead commits, never agents").
+#
+# Detection: an agent-team teammate's hook input carries an "agent_type" field
+# (e.g. "qatux"); the team lead's main session does NOT. So agent_type present
+# => a teammate (or subagent) => block git writes. Absent => the lead => allow.
+# (Empirically confirmed on Claude Code 2.1.148; docs field is "agent_type".)
+#
+# Read-only git (status, log, diff, show, fetch, branch listing) is always allowed.
+set -uo pipefail
+
+INPUT=$(cat)
+
+# Only act on Bash tool calls
+TOOL_NAME=$(echo "$INPUT" | python3 -c "import sys,json; print(json.load(sys.stdin).get('tool_name',''))" 2>/dev/null)
+[ "$TOOL_NAME" = "Bash" ] || exit 0
+
+# Teammates/subagents carry agent_type; the lead does not.
+AGENT_TYPE=$(echo "$INPUT" | python3 -c "import sys,json; print(json.load(sys.stdin).get('agent_type','') or '')" 2>/dev/null)
+[ -n "$AGENT_TYPE" ] || exit 0   # lead -> allow everything
+
+COMMAND=$(echo "$INPUT" | python3 -c "import sys,json; print(json.load(sys.stdin).get('tool_input',{}).get('command',''))" 2>/dev/null)
+
+# Block git history/working-tree-mutating subcommands anywhere in the command
+# (catches chained forms like `cd x && git commit`). Read-only git is allowed.
+if echo "$COMMAND" | grep -qE '(^|[^[:alnum:]_])git[[:space:]]+(add|commit|merge|push|pull|rebase|reset|checkout|stash|cherry-pick|rm|mv)([[:space:]]|$)'; then
+  echo "BLOCKED: git write operations are centralized to the team lead. Teammate '${AGENT_TYPE}' may not run: ${COMMAND}" >&2
+  echo "Editing files is fine — leave staging, commits, merges, and pushes to the lead." >&2
+  exit 2
+fi
+
+exit 0

.claude/rules/git-safety.md

@@ -7,6 +7,21 @@
 - Skip files in `.gitignore`
 - The `.claude/` directory IS tracked — skills and agents belong in the repo
 
+## Centralized version control (agent teams)
+
+Git is the **team lead's** job. Teammates edit files; the lead stages, commits,
+merges, and pushes. This is enforced, not just convention:
+
+- **Hook:** `.claude/hooks/git-centralize-guard.sh` (PreToolUse on Bash) blocks
+  `.git`-mutating commands — `add`, `commit`, `merge`, `push`, `pull`, `rebase`,
+  `reset`, `checkout`, `stash`, `cherry-pick`, `rm`, `mv` — for any agent-team
+  teammate. Read-only git (`status`, `log`, `diff`, `show`, `fetch`) is allowed.
+- **Detection:** a teammate's PreToolUse hook input carries an `agent_type` field
+  (e.g. `"qatux"`); the lead's main session does not. Present → block; absent →
+  allow. (Confirmed on Claude Code 2.1.148.)
+- **Activation:** hooks load at lead startup and teammates inherit that snapshot,
+  so changes to this hook require a Claude Code restart to reach teammates.
+
 ## Commit conventions
 
 Use conventional commits: `<type>(<scope>): <summary>`

.claude/settings.json

@@ -4,7 +4,7 @@
     "CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS": "1",
     "SR_DB_PATH": "/var/home/jeroenschweitzer/Projects/settled-reach/settledreach.db"
   },
-  "teammateMode": "in-process",
+  "teammateMode": "auto",
   "permissions": {
     "allow": [
       "Bash(git add *)",
@@ -87,6 +87,11 @@
             "type": "command",
             "command": ".claude/hooks/git-lock-guard.sh",
             "timeout": 5
+          },
+          {
+            "type": "command",
+            "command": ".claude/hooks/git-centralize-guard.sh",
+            "timeout": 5
           }
         ]
       }