feat: add temporal context and contextual help

docs/CONTEXTUAL_HELP_CONTRACT.md

@@ -0,0 +1,59 @@
+# Contextual Help Contract
+
+GovOPlaN exposes context-sensitive help through `F1` and the titlebar help
+control. The shell resolves a stable help identity from the focused control,
+its containing surface, and the current route. The Docs module then projects
+the best visible user or administrator topic for that identity.
+
+## Resolution Order
+
+The WebUI resolves help in this order:
+
+1. an explicit `helpContextId` or `data-help-context-id` on the focused item
+2. the focused shared control's `interfaceId`, `helpTopicId`, and label key
+3. a containing dialog, card, administration section, or page surface
+4. the current registered route, including dynamic module routes
+5. a stable route-derived fallback when no explicit identity is available
+
+Focused field and action contexts retain the page context as
+`fallback_context`. This lets Docs show a field-specific topic when one exists
+and otherwise open the owning page or module documentation instead of a generic
+help page.
+
+## Documentation Lookup
+
+Static `DocumentationTopic` contributions announce exact contexts through
+`metadata.help_contexts`. Core publishes that catalogue with the enabled module
+manifest, allowing the shell to link directly to an exact topic when possible.
+Docs still performs the authoritative audience, permission, configured-state,
+and documentation-type filtering.
+
+When there is no exact topic, Docs resolves the page fallback and then the first
+visible topic owned by the module. If Docs is unavailable, the shell opens the
+hosted documentation with the same context parameters.
+
+## Authoring Controls
+
+Core shared controls expose stable help metadata. Prefer these props rather
+than adding custom `F1` listeners:
+
+- `interfaceId` identifies a durable UI surface or action.
+- `helpContextId` identifies a documentation context when it differs from the
+  interface identity.
+- `helpTopicId` links directly to a module-owned documentation topic.
+- translated label keys provide deterministic field identities for ordinary
+  `FormField`, `ToggleSwitch`, search, date/time, email, button, dialog, and card
+  controls.
+
+Module routes, public routes, settings sections, and administration sections
+may also declare `helpContextId` and `helpTopicId`. Each module must keep a
+static user/admin documentation baseline and should list its important route,
+workflow, setting, permission, and limitation identities in
+`metadata.help_contexts`.
+
+## Boundary
+
+Help identities describe presentation context; they are not authorization
+claims. Opening help never bypasses route or documentation permissions. Docs
+owns documentation projection, feature modules own their content, and Core owns
+focus capture, context resolution, and fallback routing.