feat(seo): account-management verbs (connect/accounts/forget) + connect.sh wrapper

tokenstore remove/clear, fetch.sh forget dispatch, and a connect.sh wrapper
that sources ~/.claude/.env internally and runs from any project. /seo now
routes connect|accounts|forget before the audit flow; Makefile seo-connect
delegates to the wrapper. Labels are guarded to shell-safe ASCII (POSIX case,
whole-string, C-locale) as defense-in-depth; forget output states local
removal is not a Google-side revocation.

lib/seo-data/connect.sh

@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+# One-time OAuth consent wrapper — runnable from ANY directory:
+#   bash ~/.claude/lib/seo-data/connect.sh --label <label>
+# Sources the env vault internally (never echoed), prefers the engine venv,
+# then execs connect.py. Interactive by design: stdout carries the auth URL,
+# stderr stays visible (unlike fetch.sh, there is no secret-leak surface to
+# suppress — connect.py never prints tokens).
+set -uo pipefail
+HERE="$(cd "$(dirname "$0")" && pwd)"
+ENV_FILE="${SEO_DATA_ENV_FILE:-${HOME}/.claude/.env}"  # canonical; tests override to /dev/null
+VENV_PY="${HOME}/.claude/.venv-seo-data/bin/python3"
+
+# Whole-string label guard (shell-safe ASCII: leading alnum then alnum/._-).
+# POSIX `case` in a C-locale subshell: no per-line grep pitfall (a newline is
+# a non-allowed byte caught by *[!...]*), no locale range surprise, no second
+# grammar to differ from. Empty and non-alnum-leading are rejected too.
+_label_safe() ( LC_ALL=C; case "$1" in ''|[!A-Za-z0-9]*|*[!A-Za-z0-9._-]*) exit 1;; esac )
+
+# Strict argv grammar (parser-differential defense): accept ONLY the exact
+# forms `--label <value>` / `--store <path>` — never `=`-joined or abbreviated
+# forms — so the downstream argparse can never resolve a token this guard
+# didn't see. Runs BEFORE any secret is loaded.
+argv=("$@"); n=${#argv[@]}; i=0
+while [ "$i" -lt "$n" ]; do
+  case "${argv[$i]}" in
+    --label)
+      if ! _label_safe "${argv[$((i+1))]:-}"; then
+        echo "connect.sh: unsafe label — must match ^[A-Za-z0-9][A-Za-z0-9._-]*\$" >&2
+        exit 2
+      fi
+      i=$((i+2)) ;;
+    --store) i=$((i+2)) ;;
+    *)
+      echo "connect.sh: unsupported argument '${argv[$i]}' — usage: connect.sh --label <label> [--store <path>]" >&2
+      exit 2 ;;
+  esac
+done
+
+# Load secrets quietly (sourced, never echoed).
+if [ -f "$ENV_FILE" ]; then
+  set -a; # shellcheck source=/dev/null
+  . "$ENV_FILE"; set +a
+fi
+PY="python3"; [ -x "$VENV_PY" ] && PY="$VENV_PY"
+exec "$PY" "$HERE/connect.py" "$@"