Updates install themselves, and Linux joins

Added

• Windows: automatic updates. The app checks for a signed build, downloads and verifies it, and installs it from Settings, the title bar, or the sidebar's Update row; an unsigned or tampered download is refused.
• Windows: paste an image into a terminal and it is staged as a file whose path is typed for the agent; drop files from Explorer and their paths land in that exact terminal, translated for WSL sessions.
• Linux: signed AppImage, .deb and .rpm packages for x86_64 and aarch64 are published as release candidates.
• An agent's chats are a tab strip across the top of its page: each tab leads with its status dot, tabs reorder by dragging and keep their order across relaunches, and a right-click renames or deletes. Ctrl+N opens a new chat.
• The agent rail shows a status pip on each face, the teammate's last line beneath its name, and one trailing slot for the running count, "Needs you", or when it last spoke.
• Agents get faces: pick one in the editor when you create an agent, and it leads the header and the rail in place of the engine mark.
• Kimi Code joins the roster of coding agents you can launch.
• A Usage dashboard in the workspace menu, with a share card you can save as an image.
• Handoff: from a terminal or thread pane's ⋯ menu, hand the conversation to another teammate; it opens beside the source with the transcript and your ask as its first turn.
• An engine availability Recheck button in agent settings, so installing Claude Code or Codex mid-session is picked up without a relaunch.

Changed

• The app is called BridgeMind — in the window title, the installer, and the Start Menu shortcut.
• The sidebar no longer lists the Dashboard, Routines, Plugins, and Skills rows; the rail is the mode's list and nothing else, matching the Mac app.
• Windows: Ctrl+V in a terminal pastes text again instead of becoming an agent's image-paste control sequence.
• Terminals restored at launch stay paused until you act, so no agent process starts on its own when the app opens.
• Linux: the window uses native decorations, opens at 1280×768 so it fits a 1280×800 display, and the Browser pane is hidden where no browser surface exists.
• Creating an agent rejects an empty or duplicate name, shows character counters, and disables Create while the selected engine is not installed.

Fixed

• Linux: agent terminals no longer inherit TERM=dumb from the desktop session, so Codex and other TUIs start.
• Linux: the app starts signed out instead of crashing when the system keyring has no default collection, and an update feed without a signature reports "cannot be verified" instead of erroring.
• Routines can be created again: the form's footer is visible and Escape closes it.
• Keyboard shortcuts no longer fire while you are typing in a text field, and Ctrl+Enter in the launch wizard launches instead of opening a stray chat.
• Header chips, sidebar tooltips, and the composer no longer clip or sit under the dock on a 1280×800 display.
• Choosing a sidebar destination closes Settings instead of leaving it open over the page.