diff --git a/local/docs/HOOKS.md b/local/docs/HOOKS.md
index 28e820d20d..a8956c8725 100644
--- a/local/docs/HOOKS.md
+++ b/local/docs/HOOKS.md
@@ -74,5 +74,32 @@ in `local/scripts/` so operators can opt in by copying it to
 ## Audit
 
 This directory was created in Phase 4.5 (Round 5). The current
-hook inventory is just the 1 file above. Future hooks should be
-added here as they are created.
+hook inventory is:
+
+| Hook | File | Function |
+|------|------|----------|
+| pre-push | `local/scripts/pre-push-checks.sh` | Runs 7 pre-flight checks before push |
+| commit-msg | `local/scripts/commit-msg` | Auto-prepends `phase X.Y:` to commit messages |
+| (server-side) | (gitea admin only) | Pre-receive — defense in depth; not yet implemented |
+
+## Full Tool Inventory (Round 10)
+
+The build system has grown organically across 9+ rounds. Here is
+the complete tool inventory for reference.
+
+| Tool | Type | Purpose | Modes |
+|------|------|---------|-------|
+| `patch-status.sh` | shell | Top-level consolidated report | `--brief`, `--json` |
+| `sync-versions.sh` | shell | Cat 0+1+2 version sync | `--check`, `--no-regen`, `--regen-only` |
+| `verify-patch-content.sh` | shell↦py | Orphan patch detection | `--strict`, `--report action\|detail`, `--selftest` |
+| `verify-fork-versions.sh` | shell | Cat 2 fork supremacy check | diverged mode; `REDBEAR_STRICT_DIVERGED_CHECK=1` |
+| `verify-collision-detection.py` | python | Config [[files]] vs installs/files collision | `--strict`, `--selftest` (8 cases) |
+| `pre-push-checks.sh` | shell | 7-check pre-push safety net | `--soft` for warn-only |
+| `push-fork-branches.sh` | shell | Operator-reviewed fork push | `--execute` for actual push (default=print-only) |
+| `unblock-base-push.sh` | shell | Base fork deadlock resolver | `path-a`, `path-b`, `path-c` for 3 operator paths |
+| `commit-msg` | shell | Auto-phase-prefix hook | opt-in; install to `.git/hooks/commit-msg` |
+| `build-preflight.sh` | shell | Build-time validation | Called by `build-redbear.sh` |
+
+All scripts are under `local/scripts/` and are designed to be
+operator-friendly. Hooks are strictly opt-in per AGENTS.md
+"absolutely NEVER DELETE, NEVER IGNORE" rule.
diff --git a/local/scripts/commit-msg b/local/scripts/commit-msg
new file mode 100755
index 0000000000..e01ac8343d
--- /dev/null
+++ b/local/scripts/commit-msg
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+# commit-msg — Optional commit-msg hook for Red Bear OS.
+# Auto-prepends the current development phase to commit messages.
+# Usage:
+#   cp local/scripts/commit-msg .git/hooks/commit-msg
+#   chmod +x .git/hooks/commit-msg
+# The hook is OPT-IN. See local/docs/HOOKS.md.
+
+set -euo pipefail
+
+COMMIT_MSG_FILE="$1"
+PHASE=""
+
+# Detect current phase from the most recent "phase X.Y:" commit in log
+detect_phase() {
+    PHASE=$(git log --oneline -50 2>/dev/null | grep -oP 'phase \d+\.\d+' | head -1)
+    [ -n "$PHASE" ] || PHASE="phase"
+}
+
+detect_phase
+FIRST_LINE=$(head -1 "$COMMIT_MSG_FILE" 2>/dev/null)
+
+# Already has phase prefix or is Revert — skip
+echo "$FIRST_LINE" | grep -qE '^(phase [0-9]+\.[0-9]+):' && exit 0
+echo "$FIRST_LINE" | grep -qE '^Revert ' && exit 0
+
+# Empty or comment — skip
+[ -z "$FIRST_LINE" ] && exit 0
+echo "$FIRST_LINE" | grep -q '^#' && exit 0
+
+# Prepend phase
+sed -i "1s/^/${PHASE}: /" "$COMMIT_MSG_FILE"
+exit 0