Initial ssr repository

Convert the legacy system_sync.sh and system_restore.sh into a modular
shareable repository:

- bin/ssr CLI dispatcher with install/sync/restore/schedule/config/status
- lib/ split: common, cloud, brew, mackup, macos
- Cloud provider abstraction (icloud, dropbox, googledrive, onedrive, custom)
- launchd template for scheduled daily sync (renderable via sed)
- ssr.conf.example with whitelisted KEY=VALUE config loader
- macos-defaults.sh extracted from inline block, overridable
- install.sh bootstrap symlinks CLI into ~/.local/bin
- README with usage, config table, migration map, security notes
- Original scripts archived under legacy/ for reference

Fixes vs originals: set -euo pipefail, quoted vars, find -print0,
spctl --global-disable (was --master-disable), MACOS=".macos" bug,
zero-width char before ln, Apple Silicon brew shellenv, config injection
hardening.

Co-authored-by: Cursor <cursoragent@cursor.com>

bin/ssr-install

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+# ssr-install — local install: symlink CLI, seed config, optionally schedule.
+
+set -euo pipefail
+SSR_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# shellcheck source=../lib/common.sh
+source "$SSR_ROOT/lib/common.sh"
+
+ssr::require_macos
+
+PREFIX="${SSR_PREFIX:-$HOME/.local/bin}"
+CONFIG_DIR="${SSR_CONFIG_DIR:-$HOME/.config/ssr}"
+CONFIG_FILE="$CONFIG_DIR/ssr.conf"
+
+ssr::log "Installing ssr"
+ssr::log "  prefix:  $PREFIX"
+ssr::log "  config:  $CONFIG_FILE"
+
+ssr::ensure_dir "$PREFIX"
+ssr::ensure_dir "$CONFIG_DIR"
+
+# Symlink the main CLI so `ssr` works from anywhere.
+ln -sfn "$SSR_ROOT/bin/ssr" "$PREFIX/ssr"
+ssr::ok "Linked $PREFIX/ssr → $SSR_ROOT/bin/ssr"
+
+# Seed config from the example (do not overwrite an existing user config).
+if [[ ! -f "$CONFIG_FILE" ]]; then
+    cp "$SSR_ROOT/config/ssr.conf.example" "$CONFIG_FILE"
+    chmod 600 "$CONFIG_FILE"
+    ssr::ok "Seeded $CONFIG_FILE (chmod 600)"
+else
+    ssr::log "Config already exists, leaving untouched: $CONFIG_FILE"
+fi
+
+# Path hint if PREFIX is not on PATH.
+case ":$PATH:" in
+    *":$PREFIX:"*) ;;
+    *) ssr::warn "$PREFIX is not on your PATH — add it to your shell rc:"
+       echo "      export PATH=\"$PREFIX:\$PATH\"" ;;
+esac
+
+# Offer to enable the scheduled sync.
+if ssr::confirm "Enable daily scheduled sync (launchd)?" 30; then
+    "$SSR_ROOT/bin/ssr-schedule" on
+fi
+
+ssr::ok "Install complete. Run:  ssr status"