fix(ws): Prevent torn frames when add() fails after the frame header (closes #453) #878

Job	Run time
ESP32 (arduino-cli) - Dev	28m 41s
ESP32 (pio) - Arduino 2 (esp32-s2-saola-1)	14m 48s
ESP32 (pio) - Arduino 2 (esp32-c3-devkitc-02)	9m 44s
ESP32 (arduino-cli) - Release	32m 21s
ESP32 (pio) - Arduino 2 (esp32dev)	14m 48s
ESP32 (pio) - Arduino 2 (esp32-s3-devkitc-1)	14m 47s
ESP32 (pio) - Specific Envs (ci-no-chunk-inflight)	27m 19s
ESP32 (pio) - Arduino 3 (esp32dev)	26m 4s
ESP32 (pio) - Arduino 3 (esp32-s2-saola-1)	29m 3s
ESP32 (pio) - Specific Envs (ci-arduino-3-esp-idf-log)	26m 25s
ESP32 (pio) - Specific Envs (ci-no-json)	25m 57s
ESP32 (pio) - Specific Envs (ci-arduino-2-esp-idf-log)	14m 16s
ESP32 (pio) - Arduino 3 (esp32-p4)	27m 29s
ESP32 (pio) - Arduino 3 (esp32-c6-devkitc-1)	25m 11s
ESP32 (pio) - Arduino 3 (esp32-c3-devkitc-02)	16m 27s
ESP32 (pio) - Arduino 3 (esp32-h2-devkitm-1)	23m 20s
ESP32 (pio) - Specific Envs (ci-latest-asynctcp)	24m 41s
ESP32 (pio) - Arduino 3 (esp32-s3-devkitc-1)	30m 39s
ESP32 (pio) - Specific Envs (ci-regex)	30m 51s
	7h 22m 51s

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