fix: harden authoring schema and contract projections

web/packages/rpc/src/json-schema/authored-rpc-fixtures.ts

@@ -531,7 +531,9 @@ export const authoredRpcSchemas = {
     payload: Schema.Struct({
       workspace_id: Schema.String.pipe(Schema.minLength(1)),
       revision: PositiveIntegerSchema,
-      selected_step_id: Schema.optional(Schema.NullOr(Schema.String)),
+      selected_step_id: Schema.optional(
+        Schema.NullOr(Schema.String.pipe(Schema.minLength(1))),
+      ),
     }),
     success: Schema.Union(AuthoringContractInventorySchema, DraftWorkspaceSchema),
   },

web/packages/rpc/src/json-schema/rpc-parity.test.ts

@@ -548,7 +548,11 @@ const parityCases: ReadonlyArray<ParityCase> = [
       revision: 7,
       selected_step_id: "render",
     },
-    invalidPayload: { workspace_id: "console.demo", revision: 0 },
+    invalidPayload: {
+      workspace_id: "console.demo",
+      revision: 7,
+      selected_step_id: "",
+    },
     validSuccess: authoringContractInventory,
     invalidSuccess: {
       ...authoringContractInventory,

web/packages/rpc/src/method-registry.test.ts

@@ -61,6 +61,35 @@ describe("run operation registry", () => {
     });
   });
 
+  it("preserves explicit null and empty contract replacement semantics", async () => {
+    const { getOperationMeta } = await import("./method-registry.js");
+    const operation = getOperationMeta("workflow.draft_workspaces.set_contract");
+    if (operation === undefined) throw new Error("missing set contract operation");
+
+    const cli = operation.equivalentCli({
+      workspace_id: "console.demo",
+      revision: 7,
+      input_schema: null,
+      outcomes: [],
+    });
+
+    expect(cli).toContain("input_schema=null (no equivalent CLI clear flag)");
+    expect(cli).toContain("outcomes=[] (no equivalent CLI clear flag)");
+    expect(cli).not.toContain("--outcome");
+  });
+
+  it("renders non-empty contract outcomes as repeated CLI flags", async () => {
+    const { getOperationMeta } = await import("./method-registry.js");
+    const operation = getOperationMeta("workflow.draft_workspaces.set_contract");
+    if (operation === undefined) throw new Error("missing set contract operation");
+
+    expect(operation.equivalentCli({
+      workspace_id: "console.demo",
+      revision: 7,
+      outcomes: ["ok", "cancelled"],
+    })).toContain("--outcome ok --outcome cancelled");
+  });
+
   it("decodes start results with the start success schema", async () => {
     vi.doMock("./rpcs.js", async () => {
       const actual = await vi.importActual<typeof import("./rpcs.js")>(

web/packages/rpc/src/method-registry.ts

@@ -839,11 +839,31 @@ const operationEntries = defineOperationEntries([
         String(p.revision),
       ];
       const unavailable: string[] = [];
-      if (p.input_schema != null) unavailable.push("input_schema (use --input-schema-file)");
-      if (p.state_schema != null) unavailable.push("state_schema (use --state-schema-file)");
-      if (p.output_schema != null) unavailable.push("output_schema (use --output-schema-file)");
-      for (const outcome of p.outcomes ?? []) {
-        parts.push("--outcome", shellArg(outcome));
+      if (p.input_schema !== undefined) {
+        unavailable.push(p.input_schema === null
+          ? "input_schema=null (no equivalent CLI clear flag)"
+          : "input_schema (use --input-schema-file)");
+      }
+      if (p.state_schema !== undefined) {
+        unavailable.push(p.state_schema === null
+          ? "state_schema=null (no equivalent CLI clear flag)"
+          : "state_schema (use --state-schema-file)");
+      }
+      if (p.output_schema !== undefined) {
+        unavailable.push(p.output_schema === null
+          ? "output_schema=null (no equivalent CLI clear flag)"
+          : "output_schema (use --output-schema-file)");
+      }
+      if (p.outcomes !== undefined) {
+        if (p.outcomes === null) {
+          unavailable.push("outcomes=null (no equivalent CLI clear flag)");
+        } else if (p.outcomes.length === 0) {
+          unavailable.push("outcomes=[] (no equivalent CLI clear flag)");
+        } else {
+          for (const outcome of p.outcomes) {
+            parts.push("--outcome", shellArg(outcome));
+          }
+        }
       }
       return nonEquivalentCli(parts.join(" "), unavailable);
     },