Function CRD controller marks throttled commands as PermanentFailure without retry

## Problem

When the adx-mon Helm chart is deployed and multiple `Function` CRDs are created simultaneously, the ADX cluster throttles some `.create-or-alter` commands with:

```
The control command was aborted due to throttling. Retrying after some backoff might succeed.
CommandType: 'DatabaseScriptExecute', Capacity: 20, Origin: 'RequestRateLimitPolicy/WorkloadGroup/default'.
```

The operator marks these as `PermanentFailure` and never retries them, leaving the ADX database in an incomplete state with missing functions.

## Observed behavior

On a fresh `taugrid-test` cluster (Sweden Central, dev SKU ADX), 9 Function CRDs were created at once. 5 of 9 failed with throttling and were marked `PermanentFailure`:

```
adx-mon-audit-events PermanentFailure
adx-mon-container-metrics PermanentFailure
adx-mon-experiment-metrics-dashboard-rows PermanentFailure
adx-mon-gpu-health PermanentFailure
adx-mon-nccl-errors PermanentFailure
adx-mon-kueue-metrics Success
adx-mon-node-health Success
adx-mon-training-job-summary Success
adx-mon-xid-errors PermanentFailure
```

The portal's Fleet page then fails with `SEM0260: Unknown function: 'GpuHealth'` because the function was never created in ADX.

## Expected behavior

- Throttle errors (HTTP 429 / capacity-exceeded) should be retried with exponential backoff, not treated as permanent failures.
- Only truly permanent errors (syntax errors, permission denied, database not found) should be marked `PermanentFailure`.
- Consider staggering function creation when multiple Function CRDs are reconciled simultaneously to avoid hitting rate limits in the first place.

## Workaround

Manually execute the `.create-or-alter` commands against the ADX endpoint:

```bash
# For each failed function CRD:
BODY=$(kubectl get functions.adx-mon.azure.com -n adx-mon -o jsonpath='{.spec.body}')
# Extract the .create-or-alter command and POST to ADX /v1/rest/mgmt
```

## Environment

- adx-mon chart version: deployed via TauGrid 0.3.2 Terraform
- ADX cluster SKU: Dev(No SLA)_Standard_E2a_v4 (Sweden Central)
- Kubernetes: AKS 1.35.7
- Function CRD count: 9 (across 3 databases: Metrics, Logs, Audit)

Start by locating the Function CRD controller and the code that classifies ADX .create-or-alter command failures. Reproduce with multiple Function CRDs or the reported HTTP 429/capacity-exceeded response, then verify throttled commands retry with exponential backoff while syntax, permission, and missing-database errors remain permanent; completion should leave all functions created in ADX.

Written by the indexing model from the issue text.