Pi skill integration, CLI polish, --fix flag, config file support

- SKILL.md: Proper Agent Skills frontmatter with name/description
- pi-extension.ts: Pi extension registering 4 custom tools
  (project_map_init/patch/validate/reinit) with prompt snippets/guidelines
- pi-extension.ts: Auto-detects .pi-map.md files on session start, warns
  about dirty markers, injects maintenance hints before agent start
- package.json: Added pi.extensions and pi.skills entries
- CLI: Added picocolors, clean help screen, progress indicators,
  summary output with timing, colored check/warning icons
- validate.ts: Added --fix flag that regenerates directories with
  discrepancies
- config.ts: Reads .pi-project-map.json from project root with merge
  over defaults
- init.ts: Added optional verbose parameter for programmatic use

All 16 tests pass. TypeScript compiles clean. Build succeeds.

src/config.ts

@@ -1,3 +1,6 @@
+import { existsSync, readFileSync } from "fs";
+import { join } from "path";
+
 export interface SkillConfig {
 	ignorePatterns: string[];
 	smallPackageThreshold: number;
@@ -18,6 +21,15 @@ export const DEFAULT_CONFIG: SkillConfig = {
 		"__pycache__",
 		".DS_Store",
 		"*.log",
+		".pi-map.md",
+		".cache",
+		"tmp",
+		"temp",
+		".tmp",
+		".turbo",
+		".parcel-cache",
+		".eslintcache",
+		".prettiercache",
 	],
 	smallPackageThreshold: 10,
 	llmModel: "gpt-4o-mini",
@@ -25,7 +37,16 @@ export const DEFAULT_CONFIG: SkillConfig = {
 	autoInjectPrompt: true,
 };
 
-export function loadConfig(): SkillConfig {
-	// TODO: load from .pi-project-map.json or similar
+export function loadConfig(cwd: string = process.cwd()): SkillConfig {
+	const configPath = join(cwd, ".pi-project-map.json");
+	if (existsSync(configPath)) {
+		try {
+			const content = readFileSync(configPath, "utf8");
+			const userConfig = JSON.parse(content);
+			return { ...DEFAULT_CONFIG, ...userConfig };
+		} catch {
+			// Fall through to default
+		}
+	}
 	return DEFAULT_CONFIG;
 }