chore: v2.8.15 — Oh My Pi login sharing, omp --allow-home, Markdown Preview default, first-login password

- omp-share.js: an admin's switch (S3) runs omp's own auth broker + gateway as
  the host on loopback; a member's omp pane reaches it as a scoped client keyed
  by its pane token (clients file = live omp panes only), runs on
  --model agenthub/<model>, never holds a credential.
- omp catalog: --allow-home, so a workspace at the account's home keeps its
  sessions there (they were recorded under a temp dir and dropped).
- Settings → Appearance → Open Markdown as: Preview (default) or Raw, for
  Files/Changes, the config viewer and a chat's file panel.
- First-login password change and password rules, avatar URLs, Artifacts
  "Mine" includes installed shared skills/plugins, a member's own hook pages.

client/src/lib/api.ts

@@ -733,6 +733,8 @@ export type AuthUser = {
   /** When the account's avatar was last set (null = none) — versions its URL. */
   avatarAt?: string | null;
   createdAt?: string;
+  /** An admin gave this password: the user must choose their own before anything else. */
+  mustChangePassword?: boolean;
 };
 export type AuthState = { mode: "local" } | { mode: "server"; user: AuthUser | null };
 /** GET /api/me/prefs — the signed-in account's own UI preferences (localStorage keys). */
@@ -1007,6 +1009,9 @@ export const api = {
         body: file,
         headers: { "Content-Type": "application/octet-stream" },
       }),
+    /** POST /api/me/avatar/url — the server downloads the picture from an https link. */
+    setAvatarFromUrl: (url: string) =>
+      request<MyAccount>("/me/avatar/url", { method: "POST", body: JSON.stringify({ url }) }),
     /** DELETE /api/me/avatar — back to the initials. */
     removeAvatar: () => request<MyAccount>("/me/avatar", { method: "DELETE" }),
   },
@@ -3051,6 +3056,14 @@ export const api = {
   aiTools: {
     /** GET /api/ai-tools - the catalog, what is installed, enabled, and the default. */
     list: () => request<AiToolsView>("/ai-tools"),
+    /** GET /api/ai-tools/omp-sharing - the host's Oh My Pi login shared with members (S3). */
+    ompSharing: () => request<OmpSharingState>("/ai-tools/omp-sharing"),
+    /** PUT /api/ai-tools/omp-sharing - an admin's switch. */
+    setOmpSharing: (enabled: boolean) =>
+      request<OmpSharingState>("/ai-tools/omp-sharing", {
+        method: "PUT",
+        body: JSON.stringify({ enabled }),
+      }),
     /** POST /api/ai-tools/refresh - re-read the login shell's PATH and re-detect. */
     refresh: () => request<AiToolsView>("/ai-tools/refresh", { method: "POST" }),
     /** PUT /api/ai-tools/:id - enable/disable a tool, make it the default, or set its default model ("" clears). */
@@ -4307,6 +4320,16 @@ export interface ArtifactCandidate {
   pinned: boolean;
 }
 
+/** `GET /api/ai-tools/omp-sharing` — never a token. */
+export interface OmpSharingState {
+  /** Server mode with per-user Linux accounts (S3): the only place it applies. */
+  available: boolean;
+  enabled: boolean;
+  installed: boolean;
+  broker: { running: boolean; error?: string | null };
+  gateway: { running: boolean; port?: number; error?: string | null };
+}
+
 export interface ArtifactSettings {
   serverMode: boolean;
   canShare: boolean;