[v2] Dispatcher/ServerRunner receive-path swap — replaces BaseSession #2484

Job	Run time
checks / pre-commit	38s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 0s
checks / test (3.11, locked, ubuntu-latest)	42s
checks / test (3.10, locked, windows-latest)	1m 36s
checks / test (3.10, lowest-direct, windows-latest)	1m 13s
checks / readme-snippets	11s
checks / test (3.13, lowest-direct, windows-latest)	1m 39s
checks / test (3.11, locked, windows-latest)	1m 24s
checks / test (3.11, lowest-direct, ubuntu-latest)	37s
checks / test (3.14, locked, windows-latest)	2m 1s
checks / test (3.13, locked, ubuntu-latest)	49s
checks / test (3.10, locked, ubuntu-latest)	52s
checks / test (3.14, locked, ubuntu-latest)	1m 41s
checks / test (3.11, lowest-direct, windows-latest)	1m 30s
checks / test (3.10, lowest-direct, ubuntu-latest)	52s
checks / test (3.14, lowest-direct, ubuntu-latest)	39s
checks / test (3.13, locked, windows-latest)	1m 31s
checks / test (3.12, lowest-direct, windows-latest)	1m 51s
checks / test (3.12, locked, windows-latest)	1m 27s
checks / test (3.13, lowest-direct, ubuntu-latest)	53s
checks / test (3.12, locked, ubuntu-latest)	56s
checks / test (3.14, lowest-direct, windows-latest)	1m 18s
all-green	4s
	25m 24s

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