feat: initial project setup with gai tool

src/context.ts

@@ -0,0 +1,73 @@
+import { existsSync, readdirSync, statSync } from "node:fs";
+import { join } from "node:path";
+
+const IGNORED_DIRS = new Set([
+  "node_modules",
+  ".git",
+  "dist",
+  "out",
+  ".next",
+  "__pycache__",
+  ".cache",
+  ".turbo",
+  "coverage",
+  ".vscode",
+  ".idea",
+  "target",
+  "build",
+  ".gradle",
+  "vendor",
+]);
+
+export async function collectProjectContext(repoRoot: string): Promise<{
+  readme: string | null;
+  packageDescription: string | null;
+  structure: string | null;
+}> {
+  let readme: string | null = null;
+  let packageDescription: string | null = null;
+  let structure: string | null = null;
+
+  for (const name of ["README.md", "README.txt", "README.rst", "README"]) {
+    const filePath = join(repoRoot, name);
+    if (existsSync(filePath)) {
+      try {
+        const content = await Bun.file(filePath).text();
+        readme =
+          content.length > 1500
+            ? content.substring(0, 1500) + "\n... (truncated)"
+            : content;
+      } catch {}
+      break;
+    }
+  }
+
+  const pkgPath = join(repoRoot, "package.json");
+  if (existsSync(pkgPath)) {
+    try {
+      const pkg = (await Bun.file(pkgPath).json()) as { description?: string };
+      if (pkg.description) {
+        packageDescription = pkg.description;
+      }
+    } catch {}
+  }
+
+  try {
+    const entries = readdirSync(repoRoot)
+      .filter((name) => !IGNORED_DIRS.has(name) && !name.startsWith("."))
+      .map((name) => {
+        try {
+          return statSync(join(repoRoot, name)).isDirectory()
+            ? `${name}/`
+            : name;
+        } catch {
+          return name;
+        }
+      });
+    if (entries.length > 0) {
+      structure = entries.join(", ");
+    }
+  } catch {}
+
+  return { readme, packageDescription, structure };
+}