Open Administration on a dashboard of what the role can read

Administration used to open on its first section. It opens on a grid of
cards now: users, domains, messages waiting in the delivery queue, server
memory, and the last 24 hours' received and sent. Each card is there only
when the role holds what its number needs -- a count is a query, the
metric history a query and a get -- so a helpdesk role that reads accounts
and domains sees those two cards and nothing about the server.

What the cards count is whatever Stalwart answers for the signed-in
account, which scopes a tenant administrator's accounts, domains and queue
to the tenancy. The metric history has no tenant in it, and Stalwart's
Tenant Administrator role does not hold it, so a tenant's dashboard is
users, domains and pending.

The history is Enterprise-only and switched off by default. A server that
refuses it leaves those cards off; one that records nothing says so rather
than showing zeroes. Received and sent add up the queue counters Stalwart's
own dashboard uses, filtered with the comparison names the live server
accepts (a bare timestamp is unsupportedFilter). The column count follows
the number of cards so rows stay even, and falls back by the grid's own
width rather than the window's.

The server's test for whether an account is offered Administration matches
the client's again, now that a count is enough. The mock answers the queue
and an hourly history ending in the current hour; MOCK_METRICS=off refuses
the history as Community does, a tenant administrator gets the queue, and
helpdesk reads domains, as the demo's does.

ROADMAP and FEATURES said reporting and queues were out of scope; they say
the dashboard reads a handful of numbers and that managing queues, logs
and settings stays out. KNOWN-ISSUES records what was settled on the live
server and what was only read from source.

Fourteen new strings, in all nine catalogues.

ROADMAP.md

@@ -8,7 +8,7 @@ the rest is here because the answer is "no", not "not yet".
 
 See [KNOWN-ISSUES.md](KNOWN-ISSUES.md) for what is built but worth knowing about.
 
-- **Administration beyond accounts and domains.** The Administration menu manages accounts and domains today — see [FEATURES.md](FEATURES.md#administration). Groups, mailing lists, roles, DNS and ACME providers and tenants are Stalwart registry objects behind the same permission model, and each is a section to add rather than a design to invent; so is switching a domain's DNS, DKIM or certificate management, which is shown but not yet changed from ihasmail. Reporting, queues, logs and server settings are not planned: they are operating the server, which is Stalwart's own interface's job, not managing the people on it.
+- **Administration beyond accounts and domains.** The Administration menu opens on a dashboard and manages accounts and domains today — see [FEATURES.md](FEATURES.md#administration). Groups, mailing lists, roles, DNS and ACME providers and tenants are Stalwart registry objects behind the same permission model, and each is a section to add rather than a design to invent; so is switching a domain's DNS, DKIM or certificate management, which is shown but not yet changed from ihasmail. The dashboard reads a handful of numbers and stops there. Managing queues, reading logs and changing server settings are not planned: they are operating the server, which is Stalwart's own interface's job, not managing the people on it.
 - **Sharing a mail folder.** Stalwart stores the share and never delivers it; see [KNOWN-ISSUES.md](KNOWN-ISSUES.md). Withdrawn until the server does something with it. Sharing files, calendars and address books is unaffected and works.
 - **A scheduling view of its own**, for asking "when is everyone free next week?" without an event in hand. The grid itself is built and lives in the event editor — a row per participant, steppable, and clickable to place the event — which is where the question gets asked while you are arranging something. What is not built is the same thing as a destination you can visit with nothing in progress. Came out of [#172](https://github.com/Coffey-Labs/ihasmail/issues/172), which asked for a separate view and is closed by the panel: the reasoning for putting it in the editor is that a separate surface can only ever tell you a time you then retype, whereas one beside the event can set it. It stays here rather than in the tracker because nobody has yet said they want to ask the question on its own.
 - **Per-message actions from the message list on a touchscreen.** Reply, Forward and compose-as-new are on the list row's context menu, which is a right-click — and holding a row on a phone starts selection instead, so none of them are reachable there. They are all available inside a thread, which is where the actions on a single message belong; what is missing is the shortcut from the list. Fixing it means deciding what a long press should do when it already means something, which is a bigger question than the actions themselves.