feat(examples): postgres-backed MCP server with filesystem authorization #1953

Job	Run time
checks / pre-commit	37s
checks / readme-snippets	13s
checks / test (3.10, locked, ubuntu-latest)	54s
checks / test (3.10, locked, windows-latest)	2m 17s
checks / test (3.10, lowest-direct, ubuntu-latest)	56s
checks / test (3.10, lowest-direct, windows-latest)	3m 4s
checks / test (3.11, lowest-direct, ubuntu-latest)	58s
checks / test (3.11, lowest-direct, windows-latest)	2m 36s
checks / test (3.12, locked, ubuntu-latest)	1m 3s
checks / test (3.12, locked, windows-latest)	3m 14s
checks / test (3.13, locked, windows-latest)	2m 25s
checks / test (3.11, locked, windows-latest)	3m 5s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 0s
checks / test (3.13, lowest-direct, ubuntu-latest)	54s
checks / test (3.11, locked, ubuntu-latest)	52s
checks / test (3.13, locked, ubuntu-latest)	48s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 19s
checks / test (3.14, locked, windows-latest)	3m 0s
checks / test (3.14, locked, ubuntu-latest)	2m 18s
checks / test (3.13, lowest-direct, windows-latest)	2m 41s
checks / test (3.14, lowest-direct, windows-latest)	2m 10s
checks / test (3.12, lowest-direct, windows-latest)	3m 50s
all-green	4s
	40m 18s

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