merge: integrate main into dev

Resolve 9 merge conflicts preserving both sides' intent:
- nix hash, bootstrap hostnames rename, websocket-server wiring
- session.ts handler dedup, snapshot fallback, worktree registration
- worktree-session git service + script/setup features
- sidebar-workspace-list setup navigation, session-context cleanup
- workspace-registry-bootstrap test kept (code still exists)
- checkout-git test additions from both sides

Post-merge fixes: isPaneFocused prop rename, server type rebuild.

packages/app/src/screens/workspace/workspace-draft-agent-tab.tsx

@@ -285,7 +285,7 @@ export function WorkspaceDraftAgentTab({
           <Composer
             agentId={tabId}
             serverId={serverId}
-            isInputActive={isPaneFocused}
+            isPaneFocused={isPaneFocused}
             onSubmitMessage={handleCreateFromInput}
             isSubmitLoading={isSubmitting}
             blurOnSubmit={true}