shot2code v0.2.1

Fixes the v0.2.0 startup failure and makes update status visible in Settings.

Important: install this update manually once

v0.2.0's updater could begin replacing resources while the bundled backend and
Chromium were still exiting, producing a partial install missing native Python
modules. If v0.2.0 shows Backend did not become ready in time, download and
run v0.2.1 manually:

1. Right-click the installer -> Properties -> Unblock -> Apply
2. Close shot2code
3. Run the installer

After v0.2.1, future updates install silently and restart automatically.

Downloads

File	Use
shot2code-0.2.1-x64.exe	Recommended NSIS installer and auto-update payload
shot2code-0.2.1-x64.msi	MSI for managed deployment
shot2code-0.2.1-x64.zip	Portable build

Fixed

• Partial auto-updates. The entire backend/Copilot/Chromium process tree is
  now terminated synchronously before NSIS replaces application resources.
• Interactive update wizard. Restart & install now uses silent installation
  and relaunches the updated app.
• Missing MSI. Restored and validated by administrative extraction: exit 0,
  full payload, native pydantic extension present.

New: visible version and updater state

Settings now shows:

• The running shot2code version
• Checking / up-to-date / downloading progress / ready / error state
• Check now
• Restart & install when a download is ready

Verification

The broken local v0.2.0 installation was repaired, then v0.2.1 was installed and
verified: main window open, backend ready, bundled Chromium, Copilot and native
pydantic runtime all present.