T3 standalone update - AFTER
Commit: c04f95fe23d2b5d0123e35e7726f561d95c6ef86
Linux x64 | native CLI | fresh isolated home | loopback RPC
Local release builds: 0.1.8 -> 0.1.9 (version metadata only)
Background service launcher run directly; no system service replaced.

$ t3 --version
t3 v0.1.8
$ readlink ~/.local/bin/t3
~/.t3/runtime/versions/0.1.8/t3
$ GET /.well-known/t3/environment [version and update capability]
{"serverVersion": "0.1.8", "serverSelfUpdate": "boot-service"}

$ Update server -> 0.1.9 [same client RPC as the app]
  Update server: downloading
  Update server: installing
  Update accepted: boot-service, target 0.1.9
$ service state [after reconnection]
{"activeVersion": "0.1.9", "updateStatus": "committed"}
$ GET /.well-known/t3/environment [serverVersion]
0.1.9
$ t3 --version
t3 v0.1.9
$ readlink ~/.local/bin/t3
~/.t3/runtime/versions/0.1.9/t3
CLI agrees with updated server: TRUE

$ ln -sfn ~/.t3/runtime/versions/0.1.8/t3 ~/.local/bin/t3
$ restart background service launcher [no update request]
$ GET /.well-known/t3/environment [serverVersion]
0.1.9
$ t3 --version
t3 v0.1.8
$ readlink ~/.local/bin/t3
~/.t3/runtime/versions/0.1.8/t3
Intentional pin preserved: TRUE

Run complete. No tests or fake launcher used.