feat(profiles): first-class profile switching — phase 0 baseline port (#820)

* feat(profiles): make profile switching actually scope the app (issue #781 follow-up)

* fix(profiles): inherit connection token when switching to same-dashboard profile (issue #781 follow-up)

* fix(chat): reset open session on profile switch + prefill login profile (desktop parity)

* fix(ws): inject profile into profile-scoped RPC params so chat follows the selected profile

* test(chat): de-poison SlashCommandDispatchRpcTest (drop static Dispatchers mock)

mockkStatic(Dispatchers::class) + a stubbed Dispatchers.IO bleeds JVM-wide and
breaks later classes in suite order (CI 2026-08-06: COMMAND_DISPATCH captures
cross-wired → ComparisonFailure on lower stack PRs). ChatViewModel gains an
injected ioDispatcher (38 sites); the slash test constructs the VM with the
test dispatcher so the IO stub is unnecessary.

---------

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

app/src/main/java/com/m57/hermescontrol/ui/connect/ConnectViewModel.kt

@@ -59,7 +59,7 @@ class ConnectViewModel(
                 baseUrl = selectedProfile?.resolveBaseUrl(savedBaseUrl) ?: savedBaseUrl,
                 profiles = profiles,
                 selectedProfile = selectedProfile,
-                profileName = selectedProfile?.name ?: "",
+                profileName = selectedProfile?.name ?: selectedId ?: "",
             )
         }
         loadHealth()