Add multiple-session support: run several independent encrypted chats at once

Each conversation now runs its own WebRTC session with separate keys and SAS verification, so chats never mix. Adds a side panel to switch between open chats with unread badges, a New chat action that leaves existing chats connected, per-chat local labels stored only on this device, and an availability status (Available, Away, Busy, Invisible) shared end-to-end with connected peers. Also includes vendored Prism syntax highlighting, more reliable PWA update handling, and offline send queueing fixes. Version 4.10.0.

meta.json

@@ -1,10 +1,10 @@
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-  "buildTime": "2026-06-24T20:17:35.295Z",
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+  "version": "1782446255208",
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+  "buildTime": "2026-06-26T03:57:35.595Z",
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+  "generatedAt": "2026-06-26T03:57:35.602Z"
 }