fix(influxunifi): use CelsiusSafe() for temp fields to fix InfluxDB type conflict (#944) (#945)

* fix(influxunifi): use CelsiusSafe() for temp fields to fix InfluxDB type conflict

Write temp_* fields as float64 instead of int64 so InfluxDB does not
report 'field type conflict' when the measurement already has float.

Requires github.com/unpoller/unifi/v5 with CelsiusSafe() (unpoller/unifi#195).
Fixes #944.

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

* deps: unifi v5.17.0; nil guards and 429 retry (unpoller#943)

- Bump github.com/unpoller/unifi/v5 to v5.17.0 (CelsiusSafe, ErrNilUnifi, RateLimitError)
- inputunifi: guard pollController for nil c.Unifi; controllerID(c) in formatSites/Clients/Devices
- inputunifi: getUnifi retry with backoff on 429 (up to 5 attempts, Retry-After or exponential backoff)

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

* test(influxunifi): expect temp_* as float after CelsiusSafe() (fix #944)

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

---------

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

pkg/inputunifi/collector.go

@@ -100,6 +100,10 @@ func (u *InputUnifi) pollController(c *Controller) (*poller.Metrics, error) {
 	u.RLock()
 	defer u.RUnlock()
 
+	if c.Unifi == nil {
+		return nil, fmt.Errorf("controller client is nil (e.g. after 429 or auth failure): %s", c.URL)
+	}
+
 	u.LogDebugf("Polling controller: %s (%s)", c.URL, c.ID)
 
 	// Get the sites we care about.