feat(seats): memory, the Playwright MCP config, and the seats library

:Memory: MemAvailable and the reserve policy, the sampler of a pass's peak
tree PSS (one sweep, a pause of three sweeps at least, stopped with the
driver), and the calibration file every driver on the machine shares,
re-read and written under its lock.

:Mcp: the pinned @playwright/mcp 0.0.83 arguments and the --mcp-config of
one pass, compact and in a fixed key order.

:Seats: the dotenv loader (token lines only, TOKEN7 inert), the one-word
probe (run under the supervisor, a missing binary reported with its errno
text), the window maths, the ranking, the Fable merge, the editor-bundle
lookup of the claude binary, the redaction of anything token-shaped, and
the report. This libc++ has no tzdb, so a zone by name converts through
the C library with TZ set, reading the system's zoneinfo.

tests/Seats: 92 checks against reference vectors, numbered in order, all
green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

interfaces/Crafter.Review.cppm

@@ -23,5 +23,8 @@ export import :Totp;
 export import :Stream;
 export import :Prompt;
 export import :Config;
+export import :Memory;
+export import :Mcp;
+export import :Seats;
 export import :Freeze;
 export import :Driver;