fix(activate): unset inherited hook session vars in IDE env resolution

Agent-Logs-Url: https://github.com/version-fox/vfox/sessions/eb1376c6-75a6-4fc0-8963-99d748132fa2

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

Author: Copilot

cmd/commands/activate.go

@@ -218,6 +218,17 @@ func renderActivateScript(name, selfPath string, args []string, exportEnvs env.V
 				exportOnly[k] = v
 			}
 		}
+		// Explicitly unset hook session vars so they cannot be inherited by the
+		// IDE process. When VSCode (or other IDEs) resolves the shell
+		// environment, it spawns a login shell that inherits its own
+		// process.env. If the IDE itself was launched from a terminal where
+		// vfox was already activated, those vars leak through the captured
+		// environment into every integrated terminal, causing them to reuse
+		// the parent shell's session directory and cached state and breaking
+		// per-project version activation.
+		exportOnly[env.HookFlag] = nil
+		exportOnly[env.PidFlag] = nil
+		exportOnly[pathmeta.HookCurTmpPath] = nil
 		return s.Export(exportOnly), nil
 	}
 

cmd/commands/activate_test.go

@@ -23,9 +23,19 @@ func TestRenderActivateScriptForIDEEnvironmentResolutionSkipsHookSessionState(t
 		t.Fatalf("renderActivateScript() failed: %v", err)
 	}
 
-	for _, forbidden := range []string{env.PidFlag, env.HookFlag, pathmeta.HookCurTmpPath, "_vfox_hook"} {
-		if strings.Contains(got, forbidden) {
-			t.Fatalf("IDE environment resolution script contains %q:\n%s", forbidden, got)
+	if strings.Contains(got, "_vfox_hook") {
+		t.Fatalf("IDE environment resolution script should not register hook:\n%s", got)
+	}
+	// Hook session vars must be unset (not just omitted) so they cannot leak
+	// from the IDE's parent shell into every integrated terminal.
+	for _, key := range []string{env.PidFlag, env.HookFlag, pathmeta.HookCurTmpPath} {
+		want := "unset " + key + ";"
+		if !strings.Contains(got, want) {
+			t.Fatalf("IDE environment resolution script should unset %q, got:\n%s", key, got)
+		}
+		// And it must never re-export them.
+		if strings.Contains(got, "export "+key+"=") {
+			t.Fatalf("IDE environment resolution script should not export %q, got:\n%s", key, got)
 		}
 	}