Add Gatus auto-sync from Caddyfile, promote ensure_yq to lib/common.sh

Adds one Gatus endpoint per Caddy site block automatically, tagged
group: caddy-sync — the sync only ever adds/removes entries in that
exact group, so anything added by hand (the default external checks,
a custom endpoint) is never touched regardless of what the Caddyfile
looks like. Offered at install time (syncs once immediately) and, if
systemd is available, scheduled via a timer every 15 minutes so a site
added or removed later gets picked up without re-running the installer
— matches the "schedule that checks the Caddyfile" shape asked for.

Domain extraction tracks actual brace depth (reusing the same approach
as remove_service's Caddy block removal) rather than a naive
line-by-line scan, so it correctly skips the global options block and
parenthesized snippet definitions like (authelia) without needing to
special-case them by name.

Verified end-to-end against a real Caddyfile/config.yaml fixture with
the actual mikefarah/yq binary: initial sync adds the right entries
and leaves the default "external" group alone, a second run with no
Caddyfile changes is a true no-op (0 added, 0 removed), and changing
the Caddyfile (removing one site, adding another) correctly adds the
new endpoint and removes only the stale one.

Also fixes a real gap surfaced while building this: ensure_yq (used by
both gatus.sh now and onlyoffice.sh already) checked `command -v yq`
alone, which a box can satisfy with a completely different, incompatible
yq — confirmed live in this environment, Debian/Ubuntu's own `yq`
apt package is kislyuk/yq (a Python jq-wrapper) which silently errors
on mikefarah/yq's `e '.path' file` syntax every caller here depends on.
Now checks the version string actually identifies as mikefarah's
before trusting it, installing to /usr/local/bin (which precedes
/usr/bin on Ubuntu's default PATH) if not. Promoted ensure_yq itself
from onlyoffice.sh (its only previous user) to lib/common.sh now that
gatus.sh needs the same thing, so both share one implementation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn

services/onlyoffice.sh

@@ -191,17 +191,8 @@ fi
 
 register_service onlyoffice utilities "Self-hosted OnlyOffice Document Server (Nextcloud/FileBrowser)" 8082
 
-# ── Helper: install yq v4 if absent ──────────────────────────────────────────
-_ensure_yq() {
-    command -v yq &>/dev/null && return 0
-    log_info "Installing yq (required for FileBrowser config patching)..."
-    local _arch; _arch=$(uname -m)
-    local _binary="yq_linux_amd64"
-    [[ "$_arch" == "aarch64" || "$_arch" == "arm64" ]] && _binary="yq_linux_arm64"
-    curl -fsSL "https://github.com/mikefarah/yq/releases/latest/download/${_binary}" \
-        -o /usr/local/bin/yq && chmod +x /usr/local/bin/yq \
-        && log_success "yq installed" || log_warning "yq install failed — FileBrowser wiring skipped"
-}
+# yq install helper moved to lib/common.sh (ensure_yq) — shared with
+# services/gatus.sh now that it needs the same thing.
 
 # ── Helper: wire OnlyOffice into Nextcloud (idempotent) ───────────────────────
 _wire_nextcloud() {
@@ -228,7 +219,7 @@ _wire_nextcloud() {
 _wire_filebrowser() {
     local _fbq_config="$DOCKER_DIR/filebrowser/config.yaml"
     [[ -f "$_fbq_config" ]] || { log_info "FileBrowser config not found — skipping"; return 0; }
-    command -v yq &>/dev/null || { log_info "yq not found — skipping FileBrowser wiring"; return 0; }
+    yq --version 2>/dev/null | grep -q mikefarah || { log_info "yq unavailable or incompatible — skipping FileBrowser wiring"; return 0; }
     log_info "Wiring OnlyOffice into FileBrowser Quantum..."
     yq e '.officeServer = "http://onlyoffice:80/"' -i "$_fbq_config" \
         && log_success "FileBrowser officeServer set" || log_warning "Could not patch FileBrowser config"
@@ -237,7 +228,7 @@ _wire_filebrowser() {
 
 install_onlyoffice() {
     require_docker || return 1
-    _ensure_yq
+    declare -F ensure_yq >/dev/null 2>&1 && ensure_yq
 
     log_info "Installing OnlyOffice Document Server..."
     local DIR="$DOCKER_DIR/onlyoffice"