feat: Pi extension uses Pi's internal complete() for LLM analysis

- PiLLMClient now imports @mariozechner/pi-ai's complete() function
- Respects user's /model selection and /login auth
- No external fetch() — Pi handles transport internally
- Added src/types/pi-ai.d.ts for TypeScript declarations
- Extension reverted to real LLM calls (initProject, patchFile, reinitPath)
- Tests mock @mariozechner/pi-ai for verification

tests/pi-extension.test.ts

@@ -15,14 +15,17 @@ vi.mock("typebox", () => ({
 	},
 }));
 
+// Mock Pi's AI module so PiLLMClient works in tests
+vi.mock("@mariozechner/pi-ai", () => ({
+	complete: vi.fn(async (_model: any, _context: any) => ({
+		role: "assistant" as const,
+		content: [{ type: "text", text: "PURPOSE: Test file\nDEPS: none\nCONCEPTS: testing" }],
+	})),
+}));
+
 import extension from "../pi-extension.js";
 
-const CACHE_FILE = join(
-	homedir(),
-	".cache",
-	"pi-project-map",
-	"llm-cache.json",
-);
+const CACHE_FILE = join(homedir(), ".cache", "pi-project-map", "llm-cache.json");
 function clearCache() {
 	if (existsSync(CACHE_FILE)) unlinkSync(CACHE_FILE);
 }
@@ -40,7 +43,10 @@ describe("pi-extension", () => {
 		mockNotify = vi.fn();
 		mockCtx = {
 			cwd: "/home/project",
-			modelRegistry: {},
+			model: { provider: "openai", id: "gpt-4o-mini", api: "openai-completions" },
+			modelRegistry: {
+				getApiKeyAndHeaders: vi.fn(async () => ({ apiKey: "test-key", headers: {} })),
+			},
 			ui: { notify: mockNotify },
 		};
 
@@ -72,7 +78,7 @@ describe("pi-extension", () => {
 	});
 
 	describe("project_map_init tool", () => {
-		it("generates heuristic maps successfully", async () => {
+		it("generates maps with mocked Pi LLM", async () => {
 			const dir = mkdtempSync(join(tmpdir(), "pi-ext-test-"));
 			writeFileSync(join(dir, "test.ts"), `export const x = ${Date.now()};`);
 			mockCtx.cwd = dir;
@@ -80,12 +86,24 @@ describe("pi-extension", () => {
 			const tool = registeredTools.project_map_init;
 			const result = await tool.execute("tool-1", {}, null, null, mockCtx);
 			expect(result.details.success).toBe(true);
-			expect(result.content[0].text).toContain("Generated heuristic");
+			expect(result.content[0].text).toContain("Generated");
+		});
+
+		it("returns error when no Pi model configured", async () => {
+			const dir = mkdtempSync(join(tmpdir(), "pi-ext-test-"));
+			writeFileSync(join(dir, "test.ts"), `export const x = ${Date.now()};`);
+			mockCtx.cwd = dir;
+			mockCtx.model = null;
+
+			const tool = registeredTools.project_map_init;
+			const result = await tool.execute("tool-1", {}, null, null, mockCtx);
+			expect(result.details.success).toBe(false);
+			expect(result.content[0].text).toContain("no model configured");
 		});
 	});
 
 	describe("project_map_patch tool", () => {
-		it("patches map successfully using heuristics", async () => {
+		it("patches map with mocked Pi LLM", async () => {
 			const dir = mkdtempSync(join(tmpdir(), "pi-ext-test-"));
 			const file = join(dir, "test.ts");
 			writeFileSync(file, `export const x = ${Date.now()};`);
@@ -132,7 +150,7 @@ describe("pi-extension", () => {
 	});
 
 	describe("project_map_reinit tool", () => {
-		it("regenerates heuristic maps successfully", async () => {
+		it("regenerates maps with mocked Pi LLM", async () => {
 			const dir = mkdtempSync(join(tmpdir(), "pi-ext-test-"));
 			writeFileSync(join(dir, "test.ts"), `export const x = ${Date.now()};`);
 			mockCtx.cwd = dir;
@@ -140,7 +158,7 @@ describe("pi-extension", () => {
 			const tool = registeredTools.project_map_reinit;
 			const result = await tool.execute("tool-1", {}, null, null, mockCtx);
 			expect(result.details.success).toBe(true);
-			expect(result.content[0].text).toContain("Regenerated heuristic");
+			expect(result.content[0].text).toContain("Regenerated");
 		});
 	});