fix: simplify add-guild script using line-based insertion

skills/discord-guilds/scripts/add-guild

@@ -1,21 +1,12 @@
 #!/usr/bin/env node
-/**
- * Add a guild entry to the discord-guilds SKILL.md table
- * Usage: add-guild <guild-id> <description>
- */
-
 import fs from "node:fs";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
-
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
 const SKILL_PATH = path.resolve(__dirname, "../SKILL.md");
 
-function main() {
 const args = process.argv.slice(2);
-  
 if (args.length < 2) {
   console.error("Usage: add-guild <guild-id> <description>");
   process.exit(1);
@@ -24,33 +15,29 @@ function main() {
 const guildId = args[0];
 const description = args.slice(1).join(" ");
 
-  // Validate guild ID is numeric
 if (!/^\d+$/.test(guildId)) {
   console.error("Error: guild-id must be numeric (Discord snowflake)");
   process.exit(1);
 }
 
-  // Read existing SKILL.md
 let content = fs.readFileSync(SKILL_PATH, "utf8");
-  
-  // Find the table and insert new row
 const newRow = `| ${guildId} | ${description} |`;
 
-  // Look for the table pattern and insert after the header
-  const tablePattern = /(\| guild-id \| description \|\n\|[-\s|]+\|)/;
+// Find separator line and insert after it
+const lines = content.split("\n");
+let insertIndex = -1;
+for (let i = 0; i < lines.length; i++) {
+  if (/^\|[-\s|]+\|$/.test(lines[i]) && i > 0 && lines[i-1].includes("guild-id")) {
+    insertIndex = i;
+    break;
+  }
+}
 
-  if (!tablePattern.test(content)) {
+if (insertIndex === -1) {
   console.error("Error: Could not find guild table in SKILL.md");
   process.exit(1);
 }
 
-  // Insert new row after the table header
-  content = content.replace(tablePattern, `$1\n${newRow}`);
-  
-  // Write back
-  fs.writeFileSync(SKILL_PATH, content, "utf8");
-  
+lines.splice(insertIndex + 1, 0, newRow);
+fs.writeFileSync(SKILL_PATH, lines.join("\n"), "utf8");
 console.log(`✓ Added guild: ${guildId} - ${description}`);
-}
-
-main();