Migrate Mail surfaces to interface patterns

docs/INTERFACE_PATTERN_MIGRATION.md

@@ -0,0 +1,68 @@
+# Mail Interface Pattern Migration
+
+This inventory records the Mail-owned part of the GovOPlaN interface pattern
+language. Core owns the shell and shared components; Mail owns the transport,
+mailbox, policy, and delivery-evidence consequences described here.
+
+## Surface inventory
+
+| Surface | Primary task | Archetype | Consequence | Pattern evidence |
+| --- | --- | --- | --- | --- |
+| `/mail` folder, message, and preview panes | Browse and inspect an authorized mailbox without changing provider state | Directory/explorer | Medium because message metadata and content are private, although navigation is read-only | Full-height three-pane workspace, bounded paging, stable keyboard selection, contextual Help Center link, explicit no-profile blocker |
+| `/mail` toolbar, page filter, and pagination | Select a profile, refresh bounded indexes, and find a message on the current page | Explorer actions and local filtering | Low for refresh; medium for provider access | Shared actions expose loading/profile/folder blockers; profile transport summary is non-secret; loading and errors use Core components |
+| System/tenant/group/user/campaign profile surfaces | Compare profiles, protocol servers, reusable credentials, status, and scope | Administration/configuration | High because endpoints, credentials, and inheritance control external communication | Shared `ConnectionTree`, stable row actions, textual status, permission/target blockers, and contextual admin help |
+| Profile creation and focused profile/server/credential editors | Create a governed transport identity or edit one hierarchy object | Guided setup plus adaptive create/edit | High because saving may enable provider access or replace encrypted credentials | Shared `Dialog` and `StageRail` for multi-object setup; focused edit modes show only the selected hierarchy object; field help, connection tests, unsaved-draft guard, and disabled-save reasons |
+| Mail profile policy card | Narrow visible profiles, lower-scope definitions, hosts, senders, and recipients | Effective-policy editor | High because inherited allow/deny rules govern delivery and lower scopes | Shared policy rows, typed selectors, source path, locked/read-only blocker, dirty-save state, and contextual policy help |
+| `/mail/bounces` watcher table | Configure bounded IMAP evidence sources and run an explicit scan | Operational administration | High because it accesses a provider mailbox and changes durable evidence cursors | Shared `DataGrid`, status, loading/error feedback, field help, actionable no-profile blocker, and stable row actions |
+| `/mail/bounces` observation table | Inspect correlated or unmatched delivery-status evidence | Evidence/reporting | Medium because recipient and diagnostic data may be sensitive | Bounded sanitized rows, textual status, filters, correlation state, and no raw bounce body |
+| Bounce watcher removal | Stop future scans while retaining evidence | Destructive confirmation | Medium and reversible by recreating the watcher; observations are retained | Shared `ConfirmDialog` states the immediate consequence and retained evidence |
+| `mail.profiles` and credential-reference capabilities | Let another module select or validate Mail-owned transport without receiving secrets | Governed capability composition | High because the selected identity can perform external effects | Stable references and Core capability boundaries; no sibling-private WebUI import; authorization and credential resolution remain Mail-owned |
+
+## State and consequence contract
+
+- Loading, success, error, empty results, permission blockers, and destructive
+  confirmation use Core components. Mail does not reproduce the shell.
+- A target-dependent profile surface cannot load until a concrete user, group,
+  or campaign is selected. The blocker identifies the responsible actor and
+  destination instead of silently hiding the editor.
+- Profile, server, credential, policy, mailbox refresh, connection-test, and
+  bounce actions remain visible when structurally relevant. Missing authority,
+  required input, or an in-progress operation is exposed through a focusable
+  disabled-action explanation.
+- Connection tests never save the draft and explicitly require the relevant
+  hostname. Save remains the committing action. Policy save is unavailable
+  until a local change exists.
+- Effective policy keeps inherited source/provenance visible. A locked parent
+  limit or governed workflow cannot be represented as an editable local value.
+- Removing a bounce watcher retains observations and delivery evidence.
+  Profile/server deactivation and credential unlinking use confirmations whose
+  copy distinguishes retained reusable credentials from scrubbed owned secrets.
+- Mailbox browsing is read-only. Listing or previewing must not mark messages
+  read, move, delete, reply, or expose unbounded content.
+
+## Accessibility, responsive, and privacy evidence
+
+Shared `Dialog` owns focus entry, Escape handling, focus containment, and focus
+return. Toolbar and form DOM order is keyboard order; mailbox rows support
+Enter and Space, arrow navigation is bounded to the visible page, and disabled
+reasons are keyboard-focusable. Status always has text in addition to color.
+Contextual links identify their destination to assistive technology.
+
+Profile/policy grids collapse to one column below 900 px. The mailbox changes
+from three panes to two below 1250 px and to a single-column toolbar and message
+rows below 760 px while preserving source order and independent scroll regions.
+Long identities and transport summaries wrap or ellipsize inside stable bounds.
+
+Profile and mailbox APIs return non-secret transport metadata and bounded
+message content only. Passwords are write-only and rendered only as a saved
+state marker. Bounce observations contain bounded sanitized diagnostics and a
+raw digest, not the raw provider message. Optional Campaign, Addresses, Audit,
+Calendar, and Notifications integrations remain capability-driven; Mail WebUI
+does not import their private packages.
+
+The focused structural test guards shared components, contextual help,
+actionable blockers, confirmation, optional-module boundaries, responsive
+rules, and the absence of browser-native confirmation. Mail backend tests,
+Core component tests, manifest-shape checks, module permutations, structural
+localization audit, theme contract, and bundle budgets provide integration
+evidence.