v0.9.2: Hook setup safety and background subagent fixes

• Fix: hook setup no longer removes other tools' hooks from ~/.claude/settings.json (#73)
  • Setup (npx agent-flow-app, pnpm run setup, and the VS Code extension) treated any hook URL starting with http://127.0.0.1: as its own, so loopback HTTP hooks registered by other tools were deleted on install. On every activation, the VS Code extension also rewrote them into Agent Flow command hooks
  • Only Agent Flow's own command hook and its legacy bare-origin HTTP hook (http://127.0.0.1:<port>) are matched now. This also fixes setup being skipped when another tool's loopback hook made it look already installed
  • A settings.json that can't be parsed is now left untouched with an error, instead of being replaced by a file that only contains hooks
  • Settings are written via a temp file and rename, so an interrupted write can't truncate them
• Fix: uninstalling the VS Code extension now removes its hooks. The uninstall script was excluded from the packaged extension, so vscode:uninstall had nothing to run and Agent Flow's hooks stayed in settings.json
• Fix: background subagents were marked done the moment they launched (#92)
  • Claude Code runs Agent/Task subagents in the background by default. Their immediate tool_result only confirms the launch, but Agent Flow treated it as the finish, so the node completed at once and then looked busy again on its next tool call, or vanished and silently dropped the rest of its events
  • Background subagents now complete when their <task-notification> arrives, including ones launched before Agent Flow attached. Failed or killed runs are marked in the return summary
• Fix: per-agent model detection (#91)
  • Subagents get their model from the parent transcript (resolvedModel on the launch result), so replayed or branched sessions and subagents whose transcript is never tailed now show a model
  • Placeholder <synthetic> model ids (written on API errors and interrupts) no longer replace the real model
• Fix: in review mode, the elapsed time, scrubber knob and counters stood still while playback ran through a stretch with no events, and only caught up on the next event or on pause (#90)
• Fix: session switching and replay races in the web view (#78)
  • Re-selecting the session already on screen no longer freezes event delivery, and live events no longer skip events that hadn't been replayed yet
  • Restoring a paused snapshot no longer plays it at 1x under the LIVE badge, and the snapshot cache is cleared on reset