feat(logs): structured cron run history + read endpoint

Adds unifi_cron_runs table (one row per scheduled-task execution) and
UnifiCronRun::record() wrapper that captures start/finish/status and
exceptions. The three scheduled commands now write through it:

  - reboot-all-aps    → rebooted/failed AP names per run
  - rotate-passwords  → rotated SSIDs + PPSKs, failures (when actually
                        rotating; the "is it due" early-return is silent
                        so we don't flood the log with no-op rows every
                        minute)
  - sync-ppsk-schedules → enabled/disabled PPSKs (silent when there's
                          no work)

UnifiCronLogsController returns the most-recent 200 runs as JSON,
filterable by command + status. Behind permission:unifi.settings; no
super-admin required — read-only history is fine for any operator
who can see settings.

v1.5.0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "dashboard/unifi",
     "description": "UniFi network management, WiFi stats, and captive portal authentication for the Dashboard platform",
-    "version": "1.4.0",
+    "version": "1.5.0",
     "type": "library",
     "license": "MIT",
     "autoload": {