[v2] Dispatcher/ServerRunner receive-path swap — replaces BaseSession #2335

Job	Run time
checks / readme-snippets	14s
checks / pre-commit	36s
checks / test (3.12, locked, ubuntu-latest)	1m 5s
checks / test (3.14, lowest-direct, windows-latest)	3m 17s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 6s
checks / test (3.11, lowest-direct, ubuntu-latest)	1m 8s
checks / test (3.12, locked, windows-latest)	3m 34s
checks / test (3.11, locked, ubuntu-latest)	1m 1s
checks / test (3.14, locked, windows-latest)	3m 54s
checks / test (3.10, locked, windows-latest)	2m 42s
checks / test (3.11, locked, windows-latest)	2m 49s
checks / test (3.13, lowest-direct, windows-latest)	2m 58s
checks / test (3.13, locked, windows-latest)	3m 2s
checks / test (3.10, lowest-direct, windows-latest)	4m 4s
checks / test (3.12, lowest-direct, windows-latest)	3m 36s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 15s
checks / test (3.10, locked, ubuntu-latest)	1m 5s
checks / test (3.13, lowest-direct, ubuntu-latest)	1m 5s
checks / test (3.13, locked, ubuntu-latest)	1m 0s
checks / test (3.11, lowest-direct, windows-latest)	3m 33s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 28s
checks / test (3.14, locked, ubuntu-latest)	2m 32s
all-green	2s
	47m 6s

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