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.

server/data/ai-tools/README.md

@@ -13,7 +13,7 @@ id follows, as one more argv element — `pty-run.js` emits them in place of
 `resume` when a start carries `resumeSessionId`, and only for an id that starts
 with a letter or digit. A tool without it (and without a `launcher`) refuses a
 resume by id (`EUNSUPPORTED`) rather than start fresh under a "resume".
-Built-in: omp, Grok and Cursor (`--resume`), OpenCode (`--session`). A session id may carry `_` (OpenCode's `ses_…`).
+Built-in: omp, Grok and Cursor (`--resume`), OpenCode (`--session`). omp always gets `--allow-home`: started in its account's home (a workspace there) it would otherwise move to a temp dir, and its session would name that folder, not the workspace's. A session id may carry `_` (OpenCode's `ses_…`).
 
 ## Install / update (A2)
 

server/data/ai-tools/omp.json

@@ -4,6 +4,9 @@
   "detect": [
     "omp"
   ],
+  "args": [
+    "--allow-home"
+  ],
   "prompt": {
     "mode": "argv"
   },