feat(macos): add native desktop controls and hotkey integration

- Introduced MacOsDesktopControlManifest to manage desktop control configurations.
- Implemented MacOsDesktopControlService to handle the lifecycle of the macOS helper process.
- Created MacOsWorkflowRulesEditorWindowService for managing workflow rules through a native window.
- Developed a Swift helper for macOS that integrates with AppKit and Carbon for menu-bar controls and global hotkeys.
- Added support for recording lifecycle actions via HTTP endpoints, maintaining consistency with existing Windows functionality.
- Enhanced user experience by allowing macOS users to start/stop recordings and access settings through a menu-bar interface.
- Documented design decisions, implementation evidence, and verification tasks for the new macOS features.

openspec/specs/meeting-session/spec.md

@@ -375,3 +375,43 @@ After repairing a meeting or summary, the instructions SHALL direct the agent to
 - **WHEN** the user asks the interactive agent to fix that meeting or its summary
 - **THEN** the agent instructions direct it to inspect the matching assistant context for relevant meeting-specific memory
 - **AND** direct it to append its fixes and conclusions to that assistant context
+
+### Requirement: Interactive agent uses detected host operating-system context
+Meeting Assistant SHALL detect the host operating system when the application starts and SHALL make that immutable runtime context available to the interactive settings/logs assistant.
+
+When the detected host is Windows, the interactive assistant instructions SHALL identify Windows as the runtime platform and SHALL direct the assistant to use Windows-specific commands, paths, services, environment conventions, and desktop concepts instead of macOS concepts.
+
+When the detected host is macOS, the interactive assistant instructions SHALL identify macOS as the runtime platform and SHALL direct the assistant to use macOS-specific commands, POSIX paths, launchd services, environment conventions, and desktop concepts instead of Windows concepts.
+
+Platform-aware instructions SHALL remain present when the interactive assistant uses a configured custom initial prompt.
+
+The instructions SHALL distinguish platform-aware operational guidance from feature availability and SHALL NOT imply that detecting macOS provides Windows-only or otherwise unavailable integrations.
+
+For other detected hosts, Meeting Assistant SHALL identify the platform as unsupported for platform-specific guidance and SHALL direct the assistant to prefer portable tools and concepts rather than assuming Windows or macOS.
+
+#### Scenario: Windows host receives Windows operational guidance
+- **GIVEN** Meeting Assistant detected Windows during startup
+- **WHEN** it builds the interactive settings/logs assistant instructions
+- **THEN** the instructions identify Windows as the runtime platform
+- **AND** direct the assistant to use Windows commands and concepts
+- **AND** direct the assistant not to substitute macOS commands or concepts
+
+#### Scenario: macOS host receives macOS operational guidance
+- **GIVEN** Meeting Assistant detected macOS during startup
+- **WHEN** it builds the interactive settings/logs assistant instructions
+- **THEN** the instructions identify macOS as the runtime platform
+- **AND** direct the assistant to use macOS commands and concepts
+- **AND** direct the assistant not to substitute Windows commands or concepts
+
+#### Scenario: Custom prompt retains detected platform context
+- **GIVEN** Meeting Assistant detected macOS during startup
+- **AND** a custom interactive-assistant initial prompt is configured
+- **WHEN** it builds the interactive assistant instructions
+- **THEN** the instructions contain both the custom prompt and macOS runtime guidance
+
+#### Scenario: Unsupported host uses neutral guidance
+- **GIVEN** Meeting Assistant runs on a host other than Windows or macOS
+- **WHEN** it builds the interactive settings/logs assistant instructions
+- **THEN** the instructions do not label the host as Windows or macOS
+- **AND** direct the assistant to prefer portable tools and concepts
+