## ADDED Requirements

### Requirement: SQLite Database Support
The backend SHALL support SQLite as an alternative to MySQL for offline/standalone deployments.

#### Scenario: SQLite mode initialization
- **WHEN** `database.type` is set to `"sqlite"` in config.json
- **THEN** backend SHALL create SQLite database at `database.sqlitePath`
- **AND** initialize all required tables using SQLite-compatible syntax

#### Scenario: MySQL mode initialization
- **WHEN** `database.type` is set to `"mysql"` or not specified in config.json
- **THEN** backend SHALL connect to MySQL using credentials from `database` section
- **AND** behave exactly as before this change

#### Scenario: SQLite thread safety
- **WHEN** multiple concurrent requests access SQLite database
- **THEN** backend SHALL use thread lock to serialize database operations
- **AND** use `check_same_thread=False` for SQLite connection

#### Scenario: SQLite data persistence
- **WHEN** app is closed and reopened
- **THEN** all meeting data SHALL persist in SQLite file
- **AND** be accessible on next launch

### Requirement: Portable Extraction Path Configuration
The portable Windows build SHALL extract to a predictable folder name.

#### Scenario: Fixed extraction folder
- **WHEN** portable executable starts
- **THEN** it SHALL extract to `%TEMP%\Meeting-Assistant` instead of random UUID folder

#### Scenario: Windows Defender consistency
- **WHEN** user launches portable executable multiple times
- **THEN** Windows Defender SHALL NOT prompt for permission each time
- **BECAUSE** extraction path is consistent across launches

## MODIFIED Requirements

### Requirement: Unified Configuration Schema
All configuration for frontend, backend, and whisper SHALL be in a single `config.json` file.

#### Scenario: Backend configuration loading
- **WHEN** backend sidecar starts
- **THEN** it SHALL read database type from `config.json` backend.database.type section
- **AND** read SQLite path from `config.json` backend.database.sqlitePath section (if SQLite mode)
- **AND** read database credentials from `config.json` backend.database section (if MySQL mode)
- **AND** read API keys from `config.json` backend.externalApis section
- **AND** read auth settings from `config.json` backend.auth section

#### Scenario: Configuration priority
- **WHEN** both environment variable and config.json value exist
- **THEN** environment variable SHALL take precedence

#### Scenario: Default values
- **WHEN** configuration value is not specified
- **THEN** system SHALL use sensible defaults (host: 127.0.0.1, port: 8000, database.type: mysql)