feat(cli): add --file flag to 'dispatch send' subcommand

Add the same --file <path> support that the summon (chat) command has to the
'dispatch send' subcommand. When --file is given, the file's contents are read
and attached to the message (composed via composeMessage, identical to chat).

- args.ts: add 'file' to the send ParsedCommand, make 'text' optional, parse
  --file, and require at least one of --text or --file.
- main.ts: read the file and compose the message in the send case, using the
  composed message in both the --queue and streaming branches; update USAGE.
- args.test.ts: cover --file parsing (alone, with --text, missing value) and
  update the existing send expectations + the both-missing error message.

3 files changed, 57 insertions, 8 deletions

diff --git a/packages/cli/src/args.test.ts b/packages/cli/src/args.test.ts
index 3d07c96..7a45c02 100644
--- a/packages/cli/src/args.test.ts
+++ b/packages/cli/src/args.test.ts
@@ -320,11 +320,31 @@ describe("parseArgs", () => {
 				server: "http://localhost:24203",
 				conversationId: "deadbeef",
 				text: "hi",
+				file: undefined,
+				queue: false,
+				open: false,
+			});
+		});
+
+		it("parses 'send' with --file", () => {
+			expect(parseArgs(["send", "deadbeef", "--file", "foo.txt"], { defaultServer })).toEqual({
+				kind: "send",
+				server: "http://localhost:24203",
+				conversationId: "deadbeef",
+				text: undefined,
+				file: "foo.txt",
 				queue: false,
 				open: false,
 			});
 		});
 
+		it("parses 'send' with both --text and --file", () => {
+			const result = parseArgs(["send", "deadbeef", "--text", "hi", "--file", "f.txt"], {
+				defaultServer,
+			});
+			expect(result).toMatchObject({ kind: "send", text: "hi", file: "f.txt" });
+		});
+
 		it("parses 'send' with --queue", () => {
 			const result = parseArgs(["send", "deadbeef", "--text", "hi", "--queue"], {
 				defaultServer,
@@ -334,6 +354,7 @@ describe("parseArgs", () => {
 				server: "http://localhost:24203",
 				conversationId: "deadbeef",
 				text: "hi",
+				file: undefined,
 				queue: true,
 				open: false,
 			});
@@ -348,6 +369,7 @@ describe("parseArgs", () => {
 				server: "http://localhost:24203",
 				conversationId: "deadbeef",
 				text: "hi",
+				file: undefined,
 				queue: false,
 				open: true,
 			});
@@ -363,6 +385,7 @@ describe("parseArgs", () => {
 				server: "http://localhost:24203",
 				conversationId: "deadbeef",
 				text: "hi",
+				file: undefined,
 				queue: false,
 				open: false,
 				cwd: "/tmp",
@@ -370,10 +393,10 @@ describe("parseArgs", () => {
 			});
 		});
 
-		it("requires --text", () => {
+		it("errors when --text and --file are both missing", () => {
 			const result = parseArgs(["send", "deadbeef"], { defaultServer });
 			expect(result.kind).toBe("error");
-			if (result.kind === "error") expect(result.message).toContain("--text");
+			if (result.kind === "error") expect(result.message).toContain("--text or --file");
 		});
 
 		it("requires a conversation id", () => {
@@ -386,6 +409,12 @@ describe("parseArgs", () => {
 			const result = parseArgs(["send", "deadbeef", "--text"], { defaultServer });
 			expect(result.kind).toBe("error");
 		});
+
+		it("errors when --file has no value", () => {
+			const result = parseArgs(["send", "deadbeef", "--file"], { defaultServer });
+			expect(result.kind).toBe("error");
+			if (result.kind === "error") expect(result.message).toContain("--file requires a value");
+		});
 	});
 
 	describe("open", () => {
diff --git a/packages/cli/src/args.ts b/packages/cli/src/args.ts
index 8a63777..aaad2de 100644
--- a/packages/cli/src/args.ts
+++ b/packages/cli/src/args.ts
@@ -42,7 +42,8 @@ export type ParsedCommand =
 			readonly kind: "send";
 			readonly server: string;
 			readonly conversationId: string;
-			readonly text: string;
+			readonly text?: string | undefined;
+			readonly file?: string | undefined;
 			readonly queue: boolean;
 			readonly open: boolean;
 			readonly cwd?: string;
@@ -204,6 +205,7 @@ export function parseArgs(argv: readonly string[], opts: ParseOpts): ParsedComma
 		let server = opts.defaultServer;
 		let conversationId: string | undefined;
 		let text: string | undefined;
+		let file: string | undefined;
 		let queue = false;
 		let open = false;
 		let cwd: string | undefined;
@@ -221,6 +223,10 @@ export function parseArgs(argv: readonly string[], opts: ParseOpts): ParsedComma
 					if (i + 1 >= argv.length) return { kind: "error", message: "--text requires a value" };
 					text = argv[++i];
 					break;
+				case "--file":
+					if (i + 1 >= argv.length) return { kind: "error", message: "--file requires a value" };
+					file = argv[++i];
+					break;
 				case "--queue":
 					queue = true;
 					break;
@@ -263,8 +269,11 @@ export function parseArgs(argv: readonly string[], opts: ParseOpts): ParsedComma
 		if (conversationId === undefined) {
 			return { kind: "error", message: "'send' requires a conversation id" };
 		}
-		if (text === undefined) {
-			return { kind: "error", message: "'send' requires --text" };
+		if (!text && !file) {
+			return {
+				kind: "error",
+				message: "At least one of --text or --file is required for 'send'",
+			};
 		}
 
 		return {
@@ -272,6 +281,7 @@ export function parseArgs(argv: readonly string[], opts: ParseOpts): ParsedComma
 			server,
 			conversationId,
 			text,
+			file,
 			queue,
 			open,
 			...(cwd !== undefined && { cwd }),
diff --git a/packages/cli/src/main.ts b/packages/cli/src/main.ts
index 9dfc317..b61be07 100644
--- a/packages/cli/src/main.ts
+++ b/packages/cli/src/main.ts
@@ -29,7 +29,7 @@ const USAGE = `Usage:
   dispatch compact <conversationId> [--server <url>]
   dispatch read <conversationId> [--server <url>]
   dispatch open <conversationId> [--server <url>]
-  dispatch send <conversationId> --text "..." [--queue] [--open] [--cwd <dir>] [--effort <level>] [--workspace <id>] [--server <url>]
+  dispatch send <conversationId> --text "..." [--file <path>] [--queue] [--open] [--cwd <dir>] [--effort <level>] [--workspace <id>] [--server <url>]
   dispatch <modelName> --text "..." [--file <path>] [--cwd <dir>] [--conversation <id>] [--effort <level>] [--workspace <id>] [--server <url>] [--show-reasoning] [--open]
   dispatch --help
 
@@ -156,10 +156,20 @@ async function main(): Promise<void> {
 				process.stdout.write(`Signaled frontend to open ${conversationId}\n`);
 			}
 
+			let fileContent: string | undefined;
+			if (parsed.file) {
+				fileContent = await readFile(parsed.file, "utf-8");
+			}
+			const message = composeMessage({
+				...(parsed.text !== undefined && { text: parsed.text }),
+				...(parsed.file !== undefined && { file: parsed.file }),
+				...(fileContent !== undefined && { fileContent }),
+			});
+
 			if (parsed.queue) {
 				const queued = await enqueueMessage(
 					{ fetchImpl: globalThis.fetch },
-					{ server: parsed.server, conversationId, text: parsed.text },
+					{ server: parsed.server, conversationId, text: message },
 				);
 				const line = queued.startedTurn
 					? `Started turn for ${conversationId}`
@@ -168,7 +178,7 @@ async function main(): Promise<void> {
 			} else {
 				const request = {
 					conversationId,
-					message: parsed.text,
+					message,
 					...(parsed.cwd !== undefined && { cwd: parsed.cwd }),
 					...(parsed.reasoningEffort !== undefined && { reasoningEffort: parsed.reasoningEffort }),
 					...(parsed.workspaceId !== undefined && { workspaceId: parsed.workspaceId }),