feat: workspaces — session-orchestrator + transport-http + transport-ws + cli (Wave 2+3)

session-orchestrator: workspaceId on StartTurnInput/EnqueueInput; effective cwd
  resolution (getCwd → getEffectiveCwd); auto-create workspace on turn start;
  warm parity (same effective cwd). 93 tests (+8).
transport-http: workspace routes (GET/PUT/DELETE /workspaces, title, default-cwd);
  workspaceId threading on POST /chat + queue; ?workspaceId= filter on
  GET /conversations; DELETE /conversations/:id/cwd (clears explicit cwd);
  GET /conversations/:id/lsp uses effective cwd; slug validation. 166 tests.
transport-ws: workspaceId threading on chat.send + chat.queue. 32 tests.
cli: --workspace/-w flag; ConversationMeta test fakes fixed. 123 tests.

Full typecheck EXIT 0, biome clean. 1283 vitest + 199 transport bun pass
(1 pre-existing tool-shell failure unrelated to workspaces).

1 files changed, 50 insertions, 0 deletions

diff --git a/packages/cli/src/message.test.ts b/packages/cli/src/message.test.ts
index a3f1e0b..440ec85 100644
--- a/packages/cli/src/message.test.ts
+++ b/packages/cli/src/message.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { parseArgs } from "./args.js";
 import { buildChatRequest, composeMessage } from "./message.js";
 
 describe("composeMessage", () => {
@@ -94,4 +95,53 @@ describe("buildChatRequest", () => {
 		);
 		expect(req).not.toHaveProperty("reasoningEffort");
 	});
+
+	it("includes workspaceId when provided", () => {
+		const req = buildChatRequest(
+			{ modelName: "m", text: "x", workspaceId: "my-work", showReasoning: false },
+			{ cwd: "/work", message: "x" },
+		);
+		expect(req.workspaceId).toBe("my-work");
+	});
+
+	it("omits workspaceId when not provided", () => {
+		const req = buildChatRequest(
+			{ modelName: "m", text: "x", showReasoning: false },
+			{ cwd: "/work", message: "x" },
+		);
+		expect(req).not.toHaveProperty("workspaceId");
+	});
+});
+
+describe("workspace flag → ChatRequest", () => {
+	const defaultServer = "http://localhost:24203";
+
+	it("--workspace flag sets workspaceId on request", () => {
+		const parsed = parseArgs(["my-model", "--text", "hi", "--workspace", "my-work"], {
+			defaultServer,
+		});
+		expect(parsed.kind).toBe("chat");
+		if (parsed.kind !== "chat") return;
+		const req = buildChatRequest(parsed, { cwd: "/work", message: "hi" });
+		expect(req.workspaceId).toBe("my-work");
+	});
+
+	it("--workspace flag omitted sends no workspaceId", () => {
+		const parsed = parseArgs(["my-model", "--text", "hi"], { defaultServer });
+		expect(parsed.kind).toBe("chat");
+		if (parsed.kind !== "chat") return;
+		const req = buildChatRequest(parsed, { cwd: "/work", message: "hi" });
+		expect(req.workspaceId).toBeUndefined();
+		expect(req).not.toHaveProperty("workspaceId");
+	});
+
+	it("-w shorthand sets workspaceId on request", () => {
+		const parsed = parseArgs(["my-model", "--text", "hi", "-w", "shorthand"], {
+			defaultServer,
+		});
+		expect(parsed.kind).toBe("chat");
+		if (parsed.kind !== "chat") return;
+		const req = buildChatRequest(parsed, { cwd: "/work", message: "hi" });
+		expect(req.workspaceId).toBe("shorthand");
+	});
 });