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

doc/migration-fence-definition.md

@@ -9,6 +9,7 @@ This document defines the **migration fence** - the boundary between the legacy
 ## Current Migration Status
 
 ### ✅ Completed Components
+
 - **SQLite Database Service**: Fully implemented with absurd-sql
 - **Platform Service Layer**: Unified database interface across platforms
 - **PlatformServiceMixin**: Centralized database access with caching and utilities
@@ -17,12 +18,14 @@ This document defines the **migration fence** - the boundary between the legacy
 - **Data Export/Import**: Backup and restore functionality
 
 ### 🔄 Active Migration Components
+
 - **Settings Migration**: Core user settings transferred
 - **Account Migration**: Identity and key management
 - **Contact Migration**: User contact data (via import interface)
 - **DatabaseUtil Migration**: Moving functions to PlatformServiceMixin
 
 ### ❌ Legacy Components (Fence Boundary)
+
 - **Dexie Database**: Legacy IndexedDB storage (disabled by default)
 - **Dexie-Specific Code**: Direct database access patterns
 - **Legacy Migration Paths**: Old data transfer methods
@@ -45,6 +48,7 @@ export const PlatformServiceMixin = {
 ```
 
 **Fence Rule**: All database operations must use:
+
 - `this.$db()` for read operations
 - `this.$exec()` for write operations
 - `this.$settings()` for settings access
@@ -64,6 +68,7 @@ export class PlatformServiceFactory {
 ```
 
 **Fence Rule**: All database operations must use:
+
 - `PlatformService.dbQuery()` for read operations
 - `PlatformService.dbExec()` for write operations
 - No direct `db.` or `accountsDBPromise` access in application code
@@ -71,6 +76,7 @@ export class PlatformServiceFactory {
 ### 3. Data Access Patterns
 
 #### ✅ Allowed (Inside Fence)
+
 ```typescript
 // Use PlatformServiceMixin for all database operations
 const contacts = await this.$contacts();
@@ -79,6 +85,7 @@ const result = await this.$db("SELECT * FROM contacts WHERE did = ?", [accountDi
 ```
 
 #### ❌ Forbidden (Outside Fence)
+
 ```typescript
 // Direct Dexie access (legacy pattern)
 const contacts = await db.contacts.where('did').equals(accountDid).toArray();
@@ -98,6 +105,7 @@ export async function compareDatabases(): Promise<DataComparison> {
 ```
 
 **Fence Rule**: Migration tools are the exclusive interface between:
+
 - Legacy Dexie database
 - New SQLite database
 - Data comparison and transfer operations
@@ -107,11 +115,13 @@ export async function compareDatabases(): Promise<DataComparison> {
 ### 1. Code Development Rules
 
 #### New Feature Development
+
 - **Always** use `PlatformServiceMixin` for database operations
 - **Never** import or reference Dexie directly
 - **Always** use mixin methods like `this.$settings()`, `this.$contacts()`
 
 #### Legacy Code Maintenance
+
 - **Only** modify Dexie code for migration purposes
 - **Always** add migration tests for schema changes
 - **Never** add new Dexie-specific features
@@ -119,11 +129,13 @@ export async function compareDatabases(): Promise<DataComparison> {
 ### 2. Data Integrity Rules
 
 #### Migration Safety
+
 - **Always** create backups before migration
 - **Always** verify data integrity after migration
 - **Never** delete legacy data until verified
 
 #### Rollback Strategy
+
 - **Always** maintain ability to rollback to Dexie
 - **Always** preserve migration logs
 - **Never** assume migration is irreversible
@@ -131,6 +143,7 @@ export async function compareDatabases(): Promise<DataComparison> {
 ### 3. Testing Requirements
 
 #### Migration Testing
+
 ```typescript
 // Required test pattern for migration
 describe('Database Migration', () => {
@@ -144,6 +157,7 @@ describe('Database Migration', () => {
 ```
 
 #### Application Testing
+
 ```typescript
 // Required test pattern for application features
 describe('Feature with Database', () => {
@@ -159,6 +173,7 @@ describe('Feature with Database', () => {
 ### 1. Static Analysis
 
 #### ESLint Rules
+
 ```json
 {
   "rules": {
@@ -178,6 +193,7 @@ describe('Feature with Database', () => {
 ```
 
 #### TypeScript Rules
+
 ```json
 {
   "compilerOptions": {
@@ -190,6 +206,7 @@ describe('Feature with Database', () => {
 ### 2. Runtime Checks
 
 #### Development Mode Validation
+
 ```typescript
 // Development-only fence validation
 if (import.meta.env.DEV) {
@@ -198,6 +215,7 @@ if (import.meta.env.DEV) {
 ```
 
 #### Production Safety
+
 ```typescript
 // Production fence enforcement
 if (import.meta.env.PROD) {
@@ -209,6 +227,7 @@ if (import.meta.env.PROD) {
 ## Migration Status Checklist
 
 ### ✅ Completed
+
 - [x] PlatformServiceMixin implementation
 - [x] SQLite database service
 - [x] Migration tools
@@ -217,11 +236,13 @@ if (import.meta.env.PROD) {
 - [x] ActiveDid migration
 
 ### 🔄 In Progress
+
 - [ ] Contact migration
 - [ ] DatabaseUtil to PlatformServiceMixin migration
 - [ ] File-by-file migration
 
 ### ❌ Not Started
+
 - [ ] Legacy Dexie removal
 - [ ] Final cleanup and validation
 
@@ -240,4 +261,4 @@ if (import.meta.env.PROD) {
 **Created**: 2025-07-05
 **Status**: Active Migration Phase
 **Last Updated**: 2025-07-05
-**Note**: Migration fence now implemented through PlatformServiceMixin instead of USE_DEXIE_DB constant 
+**Note**: Migration fence now implemented through PlatformServiceMixin instead of USE_DEXIE_DB constant