## ADDED Requirements

### Requirement: Embedded Backend Packaging
The FastAPI backend SHALL be packaged as a standalone executable using PyInstaller for all-in-one deployment.

#### Scenario: Backend executable creation
- **WHEN** build script runs with embedded backend flag
- **THEN** PyInstaller SHALL create `backend/dist/backend/backend.exe` containing FastAPI, uvicorn, and all dependencies

#### Scenario: Backend executable startup
- **WHEN** backend executable is launched
- **THEN** it SHALL read configuration from `config.json` in the same directory
- **AND** start uvicorn server on configured host and port

### Requirement: Electron Backend Sidecar Management
The Electron main process SHALL manage the embedded backend as a sidecar process.

#### Scenario: Start backend on app launch
- **WHEN** Electron app launches with `backend.embedded: true` in config
- **THEN** main process SHALL spawn backend executable as child process
- **AND** pass configuration via environment variables

#### Scenario: Skip backend when disabled
- **WHEN** Electron app launches with `backend.embedded: false` in config
- **THEN** main process SHALL NOT spawn backend executable
- **AND** frontend SHALL connect to remote backend via `apiBaseUrl`

#### Scenario: Terminate backend on app close
- **WHEN** user closes Electron app
- **THEN** main process SHALL send SIGTERM to backend process
- **AND** force kill after 5 seconds if still running

### Requirement: Backend Health Check
The Electron main process SHALL verify backend readiness before showing the main window.

#### Scenario: Health check success
- **WHEN** backend `/api/health` returns HTTP 200
- **THEN** main process SHALL proceed to create main window
- **AND** set `backendReady` state to true

#### Scenario: Health check timeout
- **WHEN** backend does not respond within 30 seconds (30 attempts, 1s interval)
- **THEN** main process SHALL display error dialog
- **AND** log detailed error for debugging

#### Scenario: Health check polling
- **WHEN** health check attempt fails
- **THEN** main process SHALL retry after 1 second
- **AND** log attempt number for debugging

### 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 credentials from `config.json` backend.database section
- **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)

### Requirement: Backend Status API
The Electron app SHALL expose backend status to the renderer process.

#### Scenario: Get backend status
- **WHEN** renderer calls `window.electronAPI.getBackendStatus()`
- **THEN** it SHALL return object with `ready` boolean and `url` string

#### Scenario: Backend status in UI
- **WHEN** backend is starting
- **THEN** UI MAY display loading indicator

### Requirement: Backward Compatibility
The embedded backend feature SHALL NOT break existing separate-deployment mode.

#### Scenario: Separate deployment unchanged
- **WHEN** `backend.embedded` is false or undefined
- **THEN** system SHALL behave exactly as before this change
- **AND** frontend connects to `apiBaseUrl` without spawning local backend

#### Scenario: Existing scripts work
- **WHEN** user runs `./start.sh start` or `./scripts/setup-backend.sh`
- **THEN** backend SHALL start normally as standalone server