Release v0.9.0: Bug fixes and branding updates

Version bump from 0.2.0 to 0.9.0 with critical Android balance update
fixes and complete Electrum→Pallectrum rebranding.

Version Updates
- electrum/version.py: 0.2.0 → 0.9.0
- electrum/plugins/timelock_recovery/manifest.json: 0.2.0 → 0.9.0
- README.md: version header updated

Documentation
- README.md: Added Windows builds documentation (portable vs setup)
- CHANGELOG.md: Added comprehensive v0.9.0 release notes

Qt GUI
- Removed "Check for updates" menu item (referenced Electrum servers)
- File: electrum/gui/qt/main_window.py

electrum/plugins/timelock_recovery/manifest.json

@@ -4,5 +4,5 @@
   "author": "orenz0@protonmail.com",
   "available_for": ["qt"],
   "icon":"timelock_recovery_60.png",
-  "version": "0.2.0"
+  "version": "0.9.0"
 }