refactor(ui): remove pick-up-in-terminal, keep ConPTY as the single session entry

Two context-menu entries opened a Claude session for the same task via different
mechanisms (embedded ConPTY vs. an external wt terminal). Drop the external-terminal
path entirely, including its worker hub method, launcher plumbing, and localization
keys, since the embedded ConPTY session already covers every case it did.

tests/ClaudeDo.Worker.Tests/Planning/WindowsTerminalLauncherTests.cs

@@ -104,25 +104,9 @@ public sealed class WindowsTerminalLauncherTests
     }
 
     [Fact]
-    public void BuildResumeCommand_ResumesSessionSingleQuoted()
+    public void BuildResumeArgs_ResumesSession()
     {
-        var command = WindowsTerminalLauncher.BuildResumeCommand("claude.exe", "sess-42");
-
-        Assert.Contains("--resume", command);
-        // The session id is single-quoted so ';' and friends pass through untouched.
-        Assert.Contains("'--resume' 'sess-42'", command);
-        // A plain resume drives the real interactive TUI — no planning-only flags.
-        Assert.DoesNotContain("--permission-mode", command);
-        Assert.DoesNotContain("--append-system-prompt-file", command);
-    }
-
-    [Fact]
-    public async Task LaunchResumeAsync_WorkingDirMissing_Throws()
-    {
-        var sut = new WindowsTerminalLauncher(wtPath: "wt", claudePath: "claude");
-        var missing = Path.Combine(Path.GetTempPath(), "nonexistent_" + Guid.NewGuid());
-        var ex = await Assert.ThrowsAsync<TerminalLaunchException>(() =>
-            sut.LaunchResumeAsync(missing, "sess-1", CancellationToken.None));
-        Assert.Contains("Working directory", ex.Message);
+        var args = WindowsTerminalLauncher.BuildResumeArgs("sess-42");
+        Assert.Equal(new[] { "--resume", "sess-42" }, args);
     }
 }