feat(public-share): selectable agent-role identity + fix floating-icon overlap

Anonymous public-share AI assistant:
- Add a workspace setting `publicShareAssistantRoleId` so an admin can pick which
  agent role (identity/persona) the anonymous assistant adopts. The role's
  instructions REPLACE the built-in persona while the immutable safety framework
  is still always appended; the role's optional model override takes precedence
  over the cheap publicShareChatModel. Resolved server-authoritatively
  (workspace-scoped, soft-delete aware; disabled/missing roles fall back to the
  built-in persona, so the tool scope remains the real security boundary).
- Plumb the field through the update DTO, ai-settings service, the workspace.repo
  ALLOWED whitelist, resolve()/getMasked(), stream-time role resolution and the
  prompt/model, plus the settings UI: a new "Assistant identity" Select listing
  enabled roles (and surfacing a saved-but-disabled role explicitly).

Public-share branding / floating icon:
- Fix the AI assistant FAB overlapping the "Powered by ..." button (both were
  Affixed bottom-right): stack the FAB above the bottom-right branding.
- Rename "Powered by Docmost" -> "Powered by Gitmost" and point the link at the
  gitmost repo.

Tests: extend public-share-chat.spec (role persona replacement still appends the
safety framework, resolveShareRole edge cases, model-override precedence).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/client/src/features/share/components/share-ai-widget.tsx

@@ -93,7 +93,10 @@ export default function ShareAiWidget({ shareId, pageId }: ShareAiWidgetProps) {
 
   if (!open) {
     return (
-      <Affix position={{ bottom: 20, right: 20 }}>
+      // Offset 80px from the bottom so the FAB stacks ABOVE the bottom-right
+      // "Powered by Gitmost" branding button (share-branding.tsx) without
+      // overlapping it.
+      <Affix position={{ bottom: 80, right: 20 }}>
         <Tooltip label={t("Ask AI")} position="left">
           <ActionIcon
             size="xl"
@@ -110,7 +113,7 @@ export default function ShareAiWidget({ shareId, pageId }: ShareAiWidgetProps) {
   }
 
   return (
-    <Affix position={{ bottom: 20, right: 20 }}>
+    <Affix position={{ bottom: 80, right: 20 }}>
       <Paper
         shadow="md"
         radius="md"
@@ -119,7 +122,7 @@ export default function ShareAiWidget({ shareId, pageId }: ShareAiWidgetProps) {
           width: 360,
           maxWidth: "calc(100vw - 40px)",
           height: 480,
-          maxHeight: "calc(100vh - 40px)",
+          maxHeight: "calc(100vh - 100px)",
           display: "flex",
           flexDirection: "column",
         }}

apps/client/src/features/share/components/share-branding.tsx

@@ -2,14 +2,17 @@ import { Affix, Button } from "@mantine/core";
 
 export default function ShareBranding() {
   return (
+    // Pinned to the bottom-RIGHT corner. The AI assistant FAB
+    // (share-ai-widget.tsx) is stacked ABOVE this with a higher `bottom`
+    // offset, so the two Affix elements never overlap.
     <Affix position={{ bottom: 20, right: 20 }}>
       <Button
         variant="default"
         component="a"
         target="_blank"
-        href="https://docmost.com?ref=public-share"
+        href="https://github.com/vvzvlad/gitmost?ref=public-share"
       >
-        Powered by Docmost
+        Powered by Gitmost
       </Button>
     </Affix>
   );

apps/client/src/features/workspace/components/settings/components/ai-provider-settings.tsx

@@ -38,6 +38,8 @@ import {
   IAiSettingsUpdate,
   SttApiStyle,
 } from "@/features/workspace/services/ai-settings-service.ts";
+import { useAiRolesQuery } from "@/features/ai-chat/queries/ai-chat-query.ts";
+import { IAiRole } from "@/features/ai-chat/types/ai-chat.types.ts";
 import AiMcpServers from "./ai-mcp-servers.tsx";
 
 // No driver field: every endpoint is OpenAI-compatible, so the form carries only
@@ -47,6 +49,9 @@ const formSchema = z.object({
   chatModel: z.string(),
   // Cheap model id for the anonymous public-share assistant; empty = use chatModel.
   publicShareChatModel: z.string(),
+  // Agent-role id whose persona the public-share assistant adopts; empty =
+  // built-in locked persona.
+  publicShareAssistantRoleId: z.string(),
   embeddingModel: z.string(),
   baseUrl: z.string(),
   // Embedding-specific base URL. Empty means "use the chat base URL".
@@ -145,6 +150,10 @@ export default function AiProviderSettings() {
   const embedTest = useTestAiConnectionMutation();
   const sttTest = useTestAiConnectionMutation();
 
+  // Agent roles drive the public-share assistant identity picker. Admin-gated
+  // (the component returns early for non-admins), same as the AI settings query.
+  const { data: roles } = useAiRolesQuery(isAdmin);
+
   // Workspace-level feature toggles live in the card headers.
   const [workspace, setWorkspace] = useAtom(workspaceAtom);
   const [chatEnabled, setChatEnabled] = useState<boolean>(
@@ -187,6 +196,7 @@ export default function AiProviderSettings() {
     initialValues: {
       chatModel: "",
       publicShareChatModel: "",
+      publicShareAssistantRoleId: "",
       embeddingModel: "",
       baseUrl: "",
       embeddingBaseUrl: "",
@@ -207,6 +217,7 @@ export default function AiProviderSettings() {
     form.setValues({
       chatModel: settings.chatModel ?? "",
       publicShareChatModel: settings.publicShareChatModel ?? "",
+      publicShareAssistantRoleId: settings.publicShareAssistantRoleId ?? "",
       embeddingModel: settings.embeddingModel ?? "",
       baseUrl: settings.baseUrl ?? "",
       embeddingBaseUrl: settings.embeddingBaseUrl ?? "",
@@ -236,6 +247,9 @@ export default function AiProviderSettings() {
       // Cheap model id for the anonymous public-share assistant; empty falls
       // back to chatModel server-side.
       publicShareChatModel: values.publicShareChatModel,
+      // Agent-role id whose persona the public-share assistant adopts; empty =
+      // built-in locked persona server-side.
+      publicShareAssistantRoleId: values.publicShareAssistantRoleId,
       embeddingModel: values.embeddingModel,
       // The embedding base URL is optional; empty falls back to the chat base
       // URL server-side.
@@ -471,6 +485,34 @@ export default function AiProviderSettings() {
 
   const monoFont = "ui-monospace, Menlo, monospace";
 
+  // Public-share assistant identity options: a leading "built-in persona" entry
+  // (empty value, the server default) plus every enabled agent role. If the saved
+  // role was since disabled it is filtered out of the enabled list, so surface it
+  // explicitly (labeled "disabled") instead of letting the Select render a blank
+  // field for a still-stored id.
+  const selectedRoleId = form.values.publicShareAssistantRoleId;
+  const enabledRoles = (roles ?? []).filter((r: IAiRole) => r.enabled);
+  const selectedDisabledRole =
+    selectedRoleId.length > 0 &&
+    !enabledRoles.some((r: IAiRole) => r.id === selectedRoleId)
+      ? (roles ?? []).find((r: IAiRole) => r.id === selectedRoleId)
+      : undefined;
+  const roleOptions = [
+    { value: "", label: t("Built-in assistant persona") },
+    ...enabledRoles.map((r: IAiRole) => ({
+      value: r.id,
+      label: r.emoji ? `${r.emoji} ${r.name}` : r.name,
+    })),
+    ...(selectedDisabledRole
+      ? [
+          {
+            value: selectedDisabledRole.id,
+            label: `${selectedDisabledRole.emoji ? `${selectedDisabledRole.emoji} ` : ""}${selectedDisabledRole.name} (${t("disabled")})`,
+          },
+        ]
+      : []),
+  ];
+
   return (
     <Stack mt="sm">
       {/* Section header */}
@@ -590,6 +632,17 @@ export default function AiProviderSettings() {
             "Optional cheaper model id for the public assistant. Empty uses the chat model above.",
           )}
         </Text>
+        <Select
+          mt="sm"
+          label={t("Assistant identity")}
+          description={t(
+            "Pick an agent role whose persona the public assistant adopts. The safety rules always still apply.",
+          )}
+          data={roleOptions}
+          allowDeselect={false}
+          disabled={isLoading || !publicShareAssistantEnabled}
+          {...form.getInputProps("publicShareAssistantRoleId")}
+        />
 
         <Group mt="md" align="center">
           <Button

apps/client/src/features/workspace/services/ai-settings-service.ts

@@ -18,6 +18,9 @@ export interface IAiSettings {
   chatModel?: string;
   // Cheap model id for the anonymous public-share assistant; empty = chatModel.
   publicShareChatModel?: string;
+  // Agent-role id whose persona the public-share assistant adopts; empty =
+  // built-in locked persona.
+  publicShareAssistantRoleId?: string;
   embeddingModel?: string;
   baseUrl?: string;
   embeddingBaseUrl?: string;
@@ -45,6 +48,9 @@ export interface IAiSettingsUpdate {
   driver?: AiDriver;
   chatModel?: string;
   publicShareChatModel?: string;
+  // Agent-role id whose persona the public-share assistant adopts; empty =
+  // built-in locked persona.
+  publicShareAssistantRoleId?: string;
   embeddingModel?: string;
   baseUrl?: string;
   embeddingBaseUrl?: string;