test(delivery): isolate the seed store in the adoption-doctor e2e smoke

[davidfarah2003]

smoke:adoption-doctor-e2e had no XDG_CONFIG_HOME isolation, so it graded the operator's machine as much as the code.

The connector seed store does not live under COTAL_HOME — it sits under globalConfigDir(), which is the real ~/.config/cotal unless XDG_CONFIG_HOME says otherwise. Every cotal invocation in this suite (the delivery daemon and each doctor auth) runs the seed reconcile, and that refuses outright when the store's generation is newer than the binary being run. On any box whose store was stamped by a later release than the tip under test, three cells red with this cotal X is older than the seed store's generation Y — which reads exactly like a behaviour failure and is not one.

Its sibling implementations/manager/smoke/attach-reconnect.smoke.ts already documents and applies this. This is the same guard, in the same shape.

Evidence — red first, then green, against the same poisoned store. The version premise did not hold on a plain run here (this box's store is stamped 0.28.2 and the branch is also 0.28.2, so the refusal cannot fire, and the suite passed 3/3 un-isolated). Rather than fix an unreproduced failure, the condition was forced: a throwaway XDG_CONFIG_HOME containing cotal/seed/stamp.json at generation 99.0.0, leaving the real store untouched.

• Before, with that store: rc=1, ✗ E2E DOCTOR-BINARY 7/10, three cells carrying this cotal 0.28.2 is older than the seed store's generation 99.0.0.
• After, same store, same command: rc=0, ✓ E2E DOCTOR-BINARY 10/10, zero refusal lines — 3 runs each way.

The count is asserted as 10/10, so a cell that silently stops running still reddens.

Test-only; no shipped package changes.