feat(ux): add CTAs to EmptyState across screens (issue #618) (#627)

Turn dead-end empty states into on-ramps by wiring the existing
EmptyState actionLabel/onAction params to real next actions.

Screens wired (real, existing actions):
- Skills (installed): Browse skill hub -> setViewMode(HUB)
- Skills (hub): Retry search -> searchHub(hubQuery)
- Cron Jobs: Create your first job -> openNewJobDialog()
- MCP servers: Add a server -> toggleAddForm() (literal moved to strings.xml)
- Webhooks: Create subscription -> showCreateDialog() (literal moved to strings.xml)
- Channels: Connect a Telegram channel -> startTelegramOnboarding()
- Model: Configure model -> navigateTo(SettingsConnection)
- Sessions (history): Start a new chat -> navigateTo(ChatScreen)
- Analytics: Explore Skills or Cron jobs -> navigateTo(SkillsScreen)
- Keys (no match): Clear search -> query = ""

All new labels use strings.xml (empty_action_* / screenname_empty_*).

Deviations from issue (documented honestly):
- Toolsets, Profiles, Plugins keep Refresh. No in-app create path exists
  (toolsets are server-defined toggles; profiles/plugins have no create
  dialog wired in UI). Refresh is the correct recovery there, not a fake
  'create' CTA. Flagged for follow-up if create flows get built.
- Skills: edited the real private InstalledSkillsView in SkillsScreen.kt;
  the duplicate internal one in InstalledSkillsTab.kt is dead code.

Verified: ktlintCheck clean, assembleDebug green.

Co-authored-by: M57 <hy4ri@users.noreply.github.com>
Co-authored-by: Ronia <ronia@hermes>

app/src/main/java/com/m57/hermescontrol/ui/model/ModelScreen.kt

@@ -54,7 +54,9 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
+import com.m57.hermescontrol.NavigationController
 import com.m57.hermescontrol.R
+import com.m57.hermescontrol.SettingsConnection
 import com.m57.hermescontrol.ui.common.EmptyState
 import com.m57.hermescontrol.ui.common.ErrorState
 import com.m57.hermescontrol.ui.common.HermesScaffold
@@ -116,8 +118,8 @@ fun ModelScreen(
                 EmptyState(
                     title = stringResource(R.string.model_empty_title),
                     subtitle = stringResource(R.string.model_empty_desc),
-                    onAction = { viewModel.loadAll() },
-                    actionLabel = stringResource(R.string.content_desc_refresh),
+                    actionLabel = stringResource(R.string.empty_action_configure_model),
+                    onAction = { NavigationController.navigateTo(SettingsConnection) },
                     modifier = Modifier.padding(paddingValues),
                 )
             }