feat(launcher): LU5/LU6 — one Play button per character, and sessions say who is playing

LU5. The per-character panel offered "GUI — enter world", "GUI — character
select" and "Headless" as three equal-looking buttons, above a "Default launch
mode" combo. It now leads with one primary **Play** that enters the world as
the selected character, with Character select and Headless kept as deliberate
secondary choices.

The combo is gone. It was never consulted by anything: every launch button
passes its own mode and LauncherOrchestrator.LaunchAsync overrides the
profile's stored mode with it (CloneCharacter(character, mode)). A setting that
changes nothing is worse than no setting, and this one made the three buttons
look like they obeyed it. The stored value is untouched.

Worth recording for whoever reads the LU5 acceptance: the launcher-side
plumbing was already correct end to end — orchestrator, selector composition,
and the client's own "skip character select when a selector is present" gate.
What actually made launching a character fail was #420, a client crash on the
character-select screen, fixed separately. Every play session in the user's
cache had no character selector, which is consistent with them only ever
reaching the select-screen paths.

LU6. Rows read `server / account / character`, then the launch mode
(Gui/GuiSelect/Headless/Probe), then the raw LauncherActivityState enum name,
then a status string. The launch mode is launcher bookkeeping — it says how the
process was started, which tells the person watching nothing and is meaningless
once the client is up.

Rows now show the account, the character (or "Character select" while one is
still being chosen, "Character refresh" for a roster probe), and one plain word
derived from the host's own status stream: Starting -> Character select ->
In game -> Stopping -> Stopped / Failed. A Play launch and a character-select
launch both read "In game" once the player is actually in it.

The orchestrator now KEEPS the identity from the host's enteredWorld event
instead of only formatting it into a status sentence, so a character-select
session stops being anonymous the moment someone enters the world.

Tests: LauncherSessionRowViewModelTests (16 — every state's wording, in-game
independent of launch mode, the character-select placeholder and its
replacement, probe labelling, stop gating). Full solution 14,370 passed,
0 failed, 0 skipped under the release-gate filter.

Campaign LU slices LU5 and LU6.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/AcDream.Launcher.Tests/LauncherWindowViewModelTests.cs

@@ -28,8 +28,11 @@ public sealed class LauncherWindowViewModelTests
         Assert.Same(server, viewModel.SelectedNode);
 
         LauncherSessionRowViewModel session = Assert.Single(viewModel.Sessions);
-        Assert.Equal("Gui", session.Mode);
-        Assert.Equal("Connected", session.State);
+        // LU6: rows read as account / character / plain state. The launch mode
+        // is gone, and "Connected" is shown as what it means to a player.
+        Assert.Equal("testaccount", session.Account);
+        Assert.Equal("+Acdream", session.Character);
+        Assert.Equal("Character select", session.State);
         Assert.True(session.IsActive);
 
         Assert.True(viewModel.IsFirstRunRequired);