feat: add subscription CLI provider catalog

opus, sonnet and haiku aliases, low..max thinking, zero cost, keyless
auth. Streaming is injected.

src/agent/claude-code/constants.ts

@@ -0,0 +1,8 @@
+export const CLAUDE_CODE_PROVIDER = "claude-code";
+
+export const CLAUDE_CODE_API = "claude-code-cli";
+
+export enum ClaudeCodeError {
+	CliNotFound = "claude CLI not found",
+	NotSignedIn = "not signed in",
+}

src/agent/claude-code/provider.ts

@@ -0,0 +1,33 @@
+import { createProvider, type Api, type Model, type Provider, type SimpleStreamOptions, type StreamFunction } from "@earendil-works/pi-ai";
+
+import { CLAUDE_CODE_API, CLAUDE_CODE_PROVIDER } from "./constants.ts";
+
+const SHARED_MODEL_FIELDS = {
+	api: CLAUDE_CODE_API,
+	provider: CLAUDE_CODE_PROVIDER,
+	baseUrl: "",
+	input: ["text", "image"],
+	// Billed to the user's Claude subscription, not per token.
+	cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+	reasoning: true,
+	// The CLI has no thinking-off switch; effort low is the floor.
+	thinkingLevelMap: { off: null, minimal: null, low: "low", medium: "medium", high: "high", xhigh: "xhigh", max: "max" },
+	contextWindow: 1_000_000,
+	maxTokens: 128_000,
+} satisfies Omit<Model<Api>, "id" | "name">;
+
+export const CLAUDE_CODE_MODELS: readonly Model<Api>[] = [
+	{ ...SHARED_MODEL_FIELDS, id: "opus", name: "Claude Opus" },
+	{ ...SHARED_MODEL_FIELDS, id: "sonnet", name: "Claude Sonnet" },
+	{ ...SHARED_MODEL_FIELDS, id: "haiku", name: "Claude Haiku" },
+];
+
+export function createClaudeCodeProvider(streamSimple: StreamFunction<Api, SimpleStreamOptions>): Provider {
+	return createProvider({
+		id: CLAUDE_CODE_PROVIDER,
+		name: "Claude Code",
+		auth: { apiKey: { name: "Claude Code CLI", resolve: async () => ({ auth: {}, source: "claude CLI" }) } },
+		models: CLAUDE_CODE_MODELS,
+		api: { stream: streamSimple, streamSimple },
+	});
+}