Add helm-unittest tests for startup probe:
- Default configuration verification (tcpSocket, timing)
- Custom timing parameters (initialDelaySeconds, periodSeconds, failureThreshold)
- Alternative probe types (httpGet)
- Custom port support
- Timeout window calculation
Add NOTES.txt with startup probe information:
- Display max startup time calculation
- Explain startup probe purpose for large libraries
- Warning for very long startup timeouts
Tests ensure startup probe works correctly for slow initial startup scenarios.
Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>
