docs: comprehensive documentation updates and modernization

- Update BUILDING.md with current build system information
- Modernize various README files across the project
- Update CHANGELOG.md with recent changes
- Improve documentation consistency and formatting
- Update platform-specific documentation (iOS, Electron, Docker)
- Enhance test documentation and build guides

test-playwright/TESTING.md

@@ -5,6 +5,7 @@ Start with [README.md](./README.md). This file has more details.
 ## Test User Setup
 
 ### Register New User on Test Server
+
 On the test server, User #0 has rights to register others. Import User #0 with this seed phrase:
 
 ```bash
@@ -18,6 +19,7 @@ This corresponds to: `did:ethr:0x0000694B58C2cC69658993A90D3840C560f2F51F`
 ## Manual Testing Steps
 
 ### Identity Management
+
 1. Create multiple identifiers:
    - Go to "Your Identity" screen
    - Click "Advanced"
@@ -96,10 +98,10 @@ npx playwright test -c playwright.config-local.ts test-playwright/60-new-activit
 ```
 
 This command allows you to:
+
 - **Run a specific test file**: `test-playwright/60-new-activity.spec.ts`
 - **Filter to a specific test**: `--grep "New offers for another user"` runs only tests with that name
 - **See the browser**: `--headed` opens the browser window so you can watch the test execute
 - **Use local config**: `-c playwright.config-local.ts` uses the local configuration file
 
 This is useful when you want to observe the testing process visually rather than running tests in headless mode. It's particularly helpful for debugging test failures or understanding how the application behaves during automated testing.
-