Implement guest tool installation and management system

- Added `guest_tools.py` for standalone tool installer functionality.
- Introduced `ToolJobStore` in `tool_store.py` to manage per-VM tool job records.
- Created `ToolService` in `tools.py` for background installation workers using the guest execution channel.
- Enhanced `LifecycleService` in `lifecycle.py` to support tool installation queuing and preparation.
- Updated `guest_exec.py` to handle connection shutdown gracefully.
- Added validation and normalization functions for tool specifications.
- Implemented logging and error handling for tool installation processes.
- Ensured compatibility with Ubuntu 22.04 and ARM64/x86_64 architectures.

uvm/app.py

@@ -14,6 +14,7 @@ from .lifecycle import LifecycleService
 from .network import NetworkManager
 from .state import StateStore
 from .system import CommandRunner
+from .tools import ToolService
 
 
 @dataclass(slots=True)
@@ -24,6 +25,7 @@ class Application:
     state_store: StateStore
     installer: Installer
     lifecycle: LifecycleService
+    tools: ToolService | None = None
 
 
 def build_application(emit: Callable[[str], None] | None = print) -> Application:
@@ -41,4 +43,5 @@ def build_application(emit: Callable[[str], None] | None = print) -> Application
         state_store=state_store,
         installer=installer,
         lifecycle=lifecycle,
+        tools=ToolService(settings, state_store, lifecycle),
     )