feat: M7 proper LLM integration with dual providers, caching, and parallel batching

- Add LLM client abstraction (src/llm-client.ts) with factory pattern
- Add OpenAI-compatible external client (src/external-llm-client.ts)
- Add Kimi.com client using Anthropic-based API (src/kimi-llm-client.ts)
- Add Pi native LLM stub (src/pi-llm-client.ts) for future ExtensionAPI wiring
- Add SHA-256 disk cache at ~/.cache/pi-project-map/ (src/llm-cache.ts)
- Add parallel batching with p-limit, retry + exponential backoff (src/llm-batch.ts)
- Rewrite llm-extract.ts to use real LLM calls with structured prompts
  - File-level: PURPOSE, DEPS, CONCEPTS
  - Package-level: ROLE, ARCH
  - Context truncation, 50KB skip, cache before LLM call
- Wire CLI with --llm-provider, --llm-model, --llm-base-url flags
- Update config.ts with llmProvider, llmBaseUrl fields
- Update init.ts and patch.ts to accept optional LLMClient
- Add sample project fixture for manual testing
- Add tests: llm-cache (3), llm-batch (5), llm-integration (8 with real Kimi API),
  pi-extension (14 mocked)
- All 56 tests pass

src/init.ts

@@ -9,34 +9,45 @@ import { extractFileAST } from "./ast-extract.js";
 import { mergeFileData } from "./merge.js";
 import { writeFileSync } from "fs";
 import { join } from "path";
+import type { LLMClient } from "./llm-client.js";
+
+export interface InitOptions {
+	verbose?: boolean;
+	llmClient?: LLMClient;
+}
 
 export async function initProject(
 	rootPath: string,
-	options?: { verbose?: boolean },
+	options: InitOptions = {},
 ): Promise<void> {
 	const entries = discoverProject(rootPath);
 
 	for (const entry of entries) {
-		await generateDirectoryMap(entry);
+		await generateDirectoryMap(entry, options.llmClient);
 	}
 
-	if (options?.verbose !== false) {
+	if (options.verbose !== false) {
 		console.log(`Generated ${entries.length} .pi-map.md files`);
 	}
 }
 
 export async function generateDirectoryMap(
 	entry: DirectoryEntry,
+	llmClient?: LLMClient,
 ): Promise<FileEntry[]> {
 	const fileData: FileEntry[] = [];
 	for (const file of entry.files) {
 		const filePath = join(entry.dirPath, file);
-		const llmData = await extractFileLLM(filePath);
+		const llmData = await extractFileLLM(filePath, llmClient);
 		const astData = await extractFileAST(filePath);
 		fileData.push(mergeFileData(file, llmData, astData));
 	}
 
-	const packageData = await extractPackageLLM(entry.relativePath, fileData);
+	const packageData = await extractPackageLLM(
+		entry.relativePath,
+		fileData,
+		llmClient,
+	);
 
 	const mapData: PackageMapData = {
 		path: entry.relativePath,
@@ -53,7 +64,7 @@ export async function generateDirectoryMap(
 
 export async function reinitPath(
 	path: string,
-	options?: { verbose?: boolean },
+	options: InitOptions = {},
 ): Promise<void> {
 	// Full regeneration clears all dirty markers by overwriting every .pi-map.md
 	await initProject(path, options);