feat(cli): implement modular command architecture with build config

- Refactor CLI entry point to use modular command structure
- Add list command with placeholder implementation
- Set up type definitions for command interface
- Configure TypeScript build and package files for distribution
- Add dist output to .gitignore

src/lib/table.ts

@@ -0,0 +1,103 @@
+interface ColumnDef {
+  key: string;
+  header: string;
+  minWidth?: number;
+  maxWidth?: number;
+  width?: number;
+}
+
+function visualWidth(str: string): number {
+  let width = 0;
+  for (const ch of str) {
+    const code = ch.codePointAt(0) ?? 0;
+    // CJK Unified, Compatibility, Extension ranges, plus fullwidth forms
+    if (
+      (code >= 0x4e00 && code <= 0x9fff) ||
+      (code >= 0x3400 && code <= 0x4dbf) ||
+      (code >= 0x20000 && code <= 0x2a6df) ||
+      (code >= 0xf900 && code <= 0xfaff) ||
+      (code >= 0xff01 && code <= 0xff60) ||
+      (code >= 0xffe0 && code <= 0xffe6)
+    ) {
+      width += 2;
+    } else {
+      width += 1;
+    }
+  }
+  return width;
+}
+
+function padToWidth(str: string, targetWidth: number): string {
+  let padded = str;
+  let current = visualWidth(str);
+  while (current < targetWidth) {
+    padded += " ";
+    current += 1;
+  }
+  return padded;
+}
+
+function truncateToWidth(str: string, maxWidth: number): string {
+  let result = "";
+  let vw = 0;
+  for (const ch of str) {
+    const charW = visualWidth(ch);
+    if (vw + charW > maxWidth - 3) {
+      result += "...";
+      break;
+    }
+    result += ch;
+    vw += charW;
+  }
+  if (visualWidth(result) <= maxWidth && result.length < str.length) {
+    result += "...";
+  }
+  return result;
+}
+
+export function formatTable(columns: ColumnDef[], rows: Record<string, string>[]): string {
+  const minW = 8;
+  const maxW = 60;
+
+  const resolved = columns.map((col) => {
+    const headerW = visualWidth(col.header);
+    let dataW = 0;
+    for (const row of rows) {
+      const val = row[col.key] ?? "-";
+      dataW = Math.max(dataW, visualWidth(val));
+    }
+    const natural = Math.max(headerW, dataW);
+    const lo = col.minWidth ?? minW;
+    const hi = col.maxWidth ?? maxW;
+    const width = Math.max(lo, Math.min(hi, natural));
+    return { ...col, width };
+  });
+
+  const padCell = (col: ColumnDef, text: string): string => {
+    if (visualWidth(text) > col.width!) {
+      return truncateToWidth(text, col.width!);
+    }
+    return padToWidth(text, col.width!);
+  };
+
+  const lines: string[] = [];
+
+  const headerLine = resolved
+    .map((col) => padCell(col, col.header))
+    .join("  ");
+  lines.push(headerLine);
+
+  const sepLine = resolved
+    .map((col) => "-".repeat(col.width!))
+    .join("  ");
+  lines.push(sepLine);
+
+  for (const row of rows) {
+    const line = resolved
+      .map((col) => padCell(col, row[col.key] ?? "-"))
+      .join("  ");
+    lines.push(line);
+  }
+
+  return lines.join("\n");
+}