Add Docker hygiene, deployment manifests, and daily log digest

Prevents Docker disk bloat by adding log rotation (10MB max, 3 files)
to all container creation and update paths, auto-pruning dangling
images after deploy/remove/update, and a daily maintenance module
that cleans build cache and warns on disk thresholds.

Saves a deployment manifest in services.json at deploy time so users
can restore all their apps after a Docker purge. Adds restore-all
and restore-single endpoints that recreate containers, Caddy config,
and DNS records from the saved manifests.

Adds an hourly log collector and daily digest generator that
summarizes errors, warnings, and events across all services into
a single human-readable report with guidance on where to investigate.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

dashcaddy-api/platform-paths.js

@@ -41,6 +41,9 @@ const paths = {
   // Docker data path for app volumes
   appData: (appName) => path.join(DOCKER_DATA, appName),
 
+  // Log digest directory
+  digestDir: process.env.DIGEST_DIR || path.join(CADDY_BASE, 'digests'),
+
   // Log paths (for allowed log file access)
   allowedLogPaths: isWindows
     ? [