Added a Send to menu to every chat message and kept restrictions when sending content on (#1124)

app/AGENTS.md

@@ -32,7 +32,10 @@ Key structure:
 - **Prompt injection reports** - The user hears once per action about what the filter removed, as soon as that action ends. Content which belongs to an action carries its scope from `PromptInjectionGuardService.BeginAction` down to where it is read or filtered; whatever is filtered without a scope is reported right away. Pass the scope as a parameter, never through a field or an `AsyncLocal`: the service serves the whole app, and the message bus delivers to other receivers in the execution context of whoever sends.
 - **Paths in stored data** - A stored path to a file which AI Studio keeps below the data directory, such as a transcript or a tokenizer copy, is relative to that directory, so that a backup or a copy of the data directory works on another computer, under another user name, or on another OS. Mark such a property with `[JsonConverter(typeof(DataDirectoryRelativePathConverter))]`, for a positional record parameter with `[property: ...]`; in memory, the path stays absolute. Better still, derive the path from IDs and store none, as `VisualBriefingStore` does. Paths to files of the user stay absolute. Chats stored before v26.10.1 are migrated by a compatibility shim, see `documentation/compatibility-shims/2026-10-relative-data-paths.md`.
 - **New files and folders in the data or configuration directory** - Whoever adds a file or folder directly to the data or configuration directory, or below `plugins/` or `databases/` one which needs a decision of its own, lists it in `DataBackupContents.ENTRIES`: as part of a backup, or with the reason a backup leaves it out. A backup takes along only what is listed as included, and a restore replaces only that. An entry included in a backup also goes into `REPLACEABLE_ELEMENTS` in `runtime/src/data_restore.rs`; otherwise the runtime refuses to restore it. The folder panel on the information page shows the list to users who back up these folders with a tool of their own.
+- **Sending content on** - Content which leaves one place for another, such as the result of an assistant sent to another assistant or a text sent into the chat, travels as a `TextLaunchPayload` through `AssistantLaunchService`, together with the restrictions of where it was written (`ChatRestrictions`, see `ChatThread.CaptureRestrictions`). Never hand over a bare string: the destination would let any provider or tool see content which its source kept from them. Build the payload with `AssistantLaunchService.CreateTextPayloadAsync`, which filters what an AI wrote for prompt injections before it reaches the next model as a message of the user. An assistant which allows sending to it overrides `AssistantBase.ApplyTextLaunchPayload`, and `SendToReceiverTests` checks that every one does; the restrictions themselves are applied centrally in `AssistantBase`.
 - **JSON in model answers** - Read the JSON part of a model answer with `ModelAnswerJson`, never with a scanner of your own. It skips the prose and code fences around the JSON but checks nothing, so broken JSON reaches the deserializer unchanged and its message can go back to the model.
+- **Long menus** - MudBlazor keeps a `MudSelect` inside the window by itself, but never a `MudMenu`: a menu taller than the window runs past its edge, and its lower entries cannot be reached. Give every `MudMenu` whose entries come from data, such as the assistants or the profiles, `MaxHeight="@MenuDefaults.MAX_HEIGHT"`, so that it scrolls.
+- **Growing popovers** - MudBlazor places an open popover only when it opens, when the window changes, and when its component renders again. Content which unfolds later, such as a `MudCollapse` or an `ExpansionPanel` inside a `MudPopover`, would therefore grow out of the window. `wwwroot/app.js` places every open popover again whenever its size changes, so such content needs no code of its own. This relies on `window.mudpopoverHelper.placePopoverByNode`, which is internal to MudBlazor: check that it still exists with every new MudBlazor version.
 - **Encryption** - Initialized before Rust service is marked ready
 - **Debug environment** - Reads `startup.env` file with IPC credentials
 - **Static files and the browser cache** - When the developer starts the app from Rider, the embedded browser of Tauri keeps the static files under `wwwroot/`, such as `app.css` or a script, in its cache. The app then still shows the old file, and a change seems not to work. Whenever you changed such a file, tell the developer to clear that cache through the developer tools of the embedded browser before testing. Users of a release are not affected.