chore: Archive all pending OpenSpec proposals

Force archive the following proposals:
- add-audio-device-selector (complete)
- add-embedded-backend-packaging (19/26 tasks)
- add-flexible-deployment-options (20/21 tasks)

New specs created:
- audio-device-management (7 requirements)
- embedded-backend (8 requirements)

Updated specs:
- transcription (+2 requirements for model download progress)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

openspec/changes/archive/2025-12-22-add-flexible-deployment-options/specs/embedded-backend/spec.md

@@ -0,0 +1,57 @@
+## 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)