refactor(cli): migrate to commander framework and simplify config loading

Replace hand-rolled CLI argument parsing with Commander for command
registration and option handling. Streamline config resolution by
removing the BrickConfig type and accepting a plain source string
with BRICK_SOURCE env var support.

- Replace manual CLI dispatch with Commander-based command tree
- Simplify resolveConfig/resolveSource to a single resolveSource function
- Remove BrickConfig interface in favor of direct source string
- Move isRemote check into index-loader as a local utility
- Update loadIndex signature to accept source string directly

src/lib/config.ts

@@ -1,30 +1,8 @@
-import type { BrickConfig } from "../types/index.js";
-
 const DEFAULT_SOURCE =
   "https://gitea.synoth.com/synoth/brick-index/raw/branch/master/blocks.yaml";
 
-function parseSourceFromArgs(args: string[]): string | undefined {
-  const idx = args.indexOf("--source");
-  if (idx !== -1 && idx + 1 < args.length) {
-    return args[idx + 1];
-  }
-  return undefined;
-}
-
-function isRemoteSource(source: string): boolean {
-  return source.startsWith("http://") || source.startsWith("https://");
-}
-
-export function resolveConfig(args: string[]): BrickConfig {
-  const cliSource = parseSourceFromArgs(args);
-  if (cliSource) {
-    return { source: cliSource, isRemote: isRemoteSource(cliSource) };
-  }
-
-  const envSource = process.env.BRICK_SOURCE;
-  if (envSource) {
-    return { source: envSource, isRemote: isRemoteSource(envSource) };
-  }
-
-  return { source: DEFAULT_SOURCE, isRemote: true };
+export function resolveSource(cliSource?: string): string {
+  if (cliSource) return cliSource;
+  if (process.env.BRICK_SOURCE) return process.env.BRICK_SOURCE;
+  return DEFAULT_SOURCE;
 }

src/lib/index-loader.ts

@@ -1,24 +1,27 @@
 import { readFile } from "node:fs/promises";
 import { load } from "js-yaml";
-import type { BlockIndex, BrickConfig } from "../types/index.js";
+import type { BlockIndex } from "../types/index.js";
 
-export async function loadIndex(config: BrickConfig): Promise<BlockIndex> {
+const isRemote = (source: string): boolean =>
+  source.startsWith("http://") || source.startsWith("https://");
+
+export async function loadIndex(source: string): Promise<BlockIndex> {
   let raw: string;
 
-  if (config.isRemote) {
+  if (isRemote(source)) {
     let response: Response;
     try {
-      response = await fetch(config.source);
+      response = await fetch(source);
     } catch {
       process.stderr.write(
-        `Error: Failed to fetch index from "${config.source}"\n`
+        `Error: Failed to fetch index from "${source}"\n`
       );
       process.exit(1);
     }
 
     if (!response.ok) {
       process.stderr.write(
-        `Error: Failed to fetch index from "${config.source}" (HTTP ${response.status})\n`
+        `Error: Failed to fetch index from "${source}" (HTTP ${response.status})\n`
       );
       process.exit(1);
     }
@@ -26,12 +29,12 @@ export async function loadIndex(config: BrickConfig): Promise<BlockIndex> {
     raw = await response.text();
   } else {
     try {
-      raw = await readFile(config.source, "utf-8");
+      raw = await readFile(source, "utf-8");
     } catch (err: unknown) {
       const code = (err as NodeJS.ErrnoException)?.code;
       if (code === "ENOENT") {
         process.stderr.write(
-          `Error: Index file not found at "${config.source}"\n`
+          `Error: Index file not found at "${source}"\n`
         );
       } else {
         process.stderr.write(`Error: ${(err as Error).message}\n`);