- Refactor `AppManifest`: add new fields and rename existing ones
- Parse and validate the manifest from an app that is being installed.
- Remove deprecated `scoped()` from `Lock`
- Create `Tactility/Paths.h`
- App loading at boot now properly parses the manifest files of external apps
- Properly lock both source and destination locations during app install
- Remove LVGL path variants from `AppPaths` and `ServicePaths`
- Removed `xPath` base classes for apps and services. There's now `AppPaths` and `ServicePaths`.
- Renamed app and service paths: "data" and "system" paths are now "user data" and "assets"
## Time & Date
- Added time to statusbar widget
- Added Time & Date Settings app
- Added TimeZone app for selecting TimeZone
- Added `tt::time` namespace with timezone code
## Other changes
- Added `SystemEvent` to publish/subscribe to system wide (e.g. for init code, but also for time settings changes)
- Changed the way the statusbar widget works: now there's only 1 that gets shown/hidden, instead of 1 instance per app instance.
- Moved `lowercase()` function to new namespace: `tt::string`
- Increased T-Deck flash & PSRAM SPI frequencies to 120 MHz (from 80 MHz)
- Temporary work-around (+ TODO item) for LVGL stack size (issue with WiFi app)
- Suppress T-Deck keystroke debugging to debug level (privacy issue)
- Improved SDL dependency wiring in various `CMakeLists.txt`
- `Loader` service had some variables renamed to the newer C++ style (from previous C style)
