Avoid duplicate evaluate_system() calls during resolution manager setup (#6133)

* Avoid duplicate evaluate_system() calls during resolution manager setup

During resolution manager initialization, both the initial healthcheck call
and the subsequent setup() call would trigger evaluate_system(), causing
redundant system evaluation. All following calls in healthcheck() are
already suppressed during the setup stage, we can optimize this by
calling check_system() directly during load() instead of the full
healthcheck().

This reduces unnecessary processing during supervisor startup while
maintaining the same functional behavior.

* Call full healthcheck on setup and move diagnostics to core start

The OS Agent diagnostics if statement accesses OS Agent through D-Bus
already. This makes the exception handling inside the if statement
not really useful.

Move OS Agent diagnostics setting to core start so we can leverage
the existing global Exception handling in start() instead of
having to add another try/except block in setup(). It also covers the
if statement itself.

supervisor/core.py

@@ -196,30 +196,20 @@ class Core(CoreSysAttributes):
                 self.sys_resolution.add_unhealthy_reason(UnhealthyReason.SETUP)
                 await async_capture_exception(err)
 
-        # Set OS Agent diagnostics if needed
-        if (
-            self.sys_config.diagnostics is not None
-            and self.sys_dbus.agent.diagnostics != self.sys_config.diagnostics
-            and not self.sys_dev
-            and self.supported
-        ):
-            try:
-                await self.sys_dbus.agent.set_diagnostics(self.sys_config.diagnostics)
-            except Exception as err:  # pylint: disable=broad-except
-                _LOGGER.warning(
-                    "Could not set diagnostics to %s due to %s",
-                    self.sys_config.diagnostics,
-                    err,
-                )
-                await async_capture_exception(err)
-
-        # Evaluate the system
-        await self.sys_resolution.evaluate.evaluate_system()
-
     async def start(self) -> None:
         """Start Supervisor orchestration."""
         await self.set_state(CoreState.STARTUP)
 
+        # Set OS Agent diagnostics if needed
+        if (
+            self.sys_dbus.agent.is_connected
+            and self.sys_config.diagnostics is not None
+            and self.sys_dbus.agent.diagnostics != self.sys_config.diagnostics
+            and self.supported
+        ):
+            _LOGGER.debug("Set OS Agent diagnostics to %s", self.sys_config.diagnostics)
+            await self.sys_dbus.agent.set_diagnostics(self.sys_config.diagnostics)
+
         # Check if system is healthy
         if not self.supported:
             _LOGGER.warning("System running in a unsupported environment!")

supervisor/resolution/module.py

@@ -215,7 +215,7 @@ class ResolutionManager(FileConfiguration, CoreSysAttributes):
 
     async def load(self):
         """Load the resoulution manager."""
-        # Initial healthcheck when the manager is loaded
+        # Initial healthcheck check
         await self.healthcheck()
 
         # Schedule the healthcheck