feat: add shared filter to workspaces query (#19807)

Adds a `shared:<boolean>` search query to the `/workspaces [get]`
endpoint


https://github.com/user-attachments/assets/ccf84bd9-c1fd-4085-825b-2e3176a2d488

Closes
[coder/internal#972](https://github.com/coder/internal/issues/972)

coderd/searchquery/search.go

@@ -225,6 +225,7 @@ func Workspaces(ctx context.Context, db database.Store, query string, page coder
 	filter.HasAITask = parser.NullableBoolean(values, sql.NullBool{}, "has-ai-task")
 	filter.HasExternalAgent = parser.NullableBoolean(values, sql.NullBool{}, "has_external_agent")
 	filter.OrganizationID = parseOrganization(ctx, db, parser, values, "organization")
+	filter.Shared = parser.NullableBoolean(values, sql.NullBool{}, "shared")
 
 	type paramMatch struct {
 		name  string

coderd/searchquery/search_test.go

@@ -282,6 +282,36 @@ func TestSearchWorkspace(t *testing.T) {
 				},
 			},
 		},
+		{
+			Name:  "SharedTrue",
+			Query: "shared:true",
+			Expected: database.GetWorkspacesParams{
+				Shared: sql.NullBool{
+					Bool:  true,
+					Valid: true,
+				},
+			},
+		},
+		{
+			Name:  "SharedFalse",
+			Query: "shared:false",
+			Expected: database.GetWorkspacesParams{
+				Shared: sql.NullBool{
+					Bool:  false,
+					Valid: true,
+				},
+			},
+		},
+		{
+			Name:  "SharedMissing",
+			Query: "",
+			Expected: database.GetWorkspacesParams{
+				Shared: sql.NullBool{
+					Bool:  false,
+					Valid: false,
+				},
+			},
+		},
 
 		// Failures
 		{