fix: set the Windows node up at sign-in, and stop it for real

Found by the first Windows beta tester, then reproduced on a clean install.

After a service-mode install nothing set the node up for the account that
signed in: the boot task started a node that quit ("hub.username not set"),
and the sidebar showed Node / Create group only once the hub held a node key.
The only way to the wizard that provisions was the home page's welcome card,
which an account already in a group never sees. The way out was
`meshbay-node init` and the key pasted on the profile page -- which is also
what PACKAGING-GUIDE.md told people to do.

- main.js `node:ensure`, called by app.js at sign-in: provisions, starts and
  links the node this build ships (Windows, bundled node only). A node set up
  for another account, or an account linked to another node, is left alone.
  node:start waits for it, so the two never race.
- The sidebar shows the Node section when a node exists on this machine.
- The Node page's status is the node's: its control API and the process
  list, not the service task's state (a node started from a terminal ran
  while the page said Stopped). Stop says Stopped only once no
  meshbay-node.exe is left, and stays offered for a process that answers
  nothing.
- CLI stop kills the pid that answered when a graceful stop does not finish,
  and fails with the reason when a node process is still there.
- The daemon ends its process 3s after _shutdown(): Python's exit waited for a
  busy indexer thread, with the control API already closed. Armed by main()
  only, never by a daemon run inside a test.
- node.toml is read as utf-8-sig (PowerShell 5.1 writes a BOM), and a config
  that cannot be read is logged instead of dying silently in service mode.
- "Pair this browser" queues the code for the next group of this node to
  open instead of saying "Paired successfully"; no banner before a group.
- test_e2e_windows_app.py (opt-in, MESHBAY_WIN_E2E=1) drives the installed
  app against a throwaway hub: fresh account to linked node, Stop, Start,
  Restart, checked against the real processes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/config.py b/packages/meshbay-node/src/meshbay_node/config.py
index 2cd8a8f..eb694ae 100644
--- a/packages/meshbay-node/src/meshbay_node/config.py
+++ b/packages/meshbay-node/src/meshbay_node/config.py
@@ -403,7 +403,11 @@ def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
     cfg = Config()
 
     if path.exists():
-        raw = tomllib.loads(path.read_text(encoding="utf-8"))
+        # utf-8-sig: Windows PowerShell 5.1's `Set-Content -Encoding utf8` and
+        # older Notepads write a BOM, which TOML refuses -- and a service node
+        # then stopped before it had said anything (found editing node.toml
+        # on a real install).
+        raw = tomllib.loads(path.read_text(encoding="utf-8-sig"))
 
         hub = raw.get("hub", {})
         cfg.hub.url      = hub.get("url",      cfg.hub.url)