docs: state the sharing boundary that is actually enforced

Two sentences promised that a manage grant reaches no settings at all. Both
were true when they were written and stopped being true when the anamnesis
destination opened, and both are in the worst places for a stale promise: one
is the access description generated into the public contract and read by the
native client, the other is the paragraph a delegate meets on a page sharing
does not cover.

Both now name the boundary the code draws — record content versus account
configuration — and say which part of the record a manage grant reaches. What
stays with the account owner is spelled out rather than implied: login, the
second factor, provider connections, tokens, notification routing, module and
threshold configuration, and who else has access.

A guard checks the copy against the classification rather than against itself,
so opening a second destination or closing this one moves the sentence with it.
The contract is regenerated.

src/lib/validations/account-sharing.ts

@@ -58,7 +58,7 @@ export const inviteGrantSchema = z
       .enum(["READ", "WRITE", "MANAGE"])
       .default("READ")
       .describe(
-        "READ can read the record and change nothing. WRITE can additionally ADD entries (readings, results, observations, a medication, a marked dose) and can still edit or delete nothing, including its own. MANAGE can additionally change and remove entries, including ones the owner wrote, and read the generated insights; it never reaches the identity surfaces (login, second factor, connections, tokens, settings, or who else has access). Omitted means READ, so a client that predates the field keeps working. The level is fixed when the invitation is written: no endpoint raises a live grant, because that would widen what the delegate accepted without asking them again. The way up is a new invitation the delegate accepts.",
+        "READ can read the record and change nothing. WRITE can additionally ADD entries (readings, results, observations, a medication, a marked dose) and can still edit or delete nothing, including its own. MANAGE can additionally change and remove entries, including ones the owner wrote, read the generated insights, and record the record's own health background (allergies, family history). The boundary is record content versus account configuration: MANAGE never reaches login, the second factor, provider connections, API tokens, notification routing, module and threshold configuration, or who else has access. Omitted means READ, so a client that predates the field keeps working. The level is fixed when the invitation is written: no endpoint raises a live grant, because that would widen what the delegate accepted without asking them again. The way up is a new invitation the delegate accepts.",
       ),
     /**
      * v1.37.0 — which sections of the record the invitation opens.