feat: support linking directly to ~/.config/opencode

When running from the OpenCode user config directory (~/.config/opencode),
plugins are now linked directly there instead of to a .opencode subdirectory.

Changes:
- Add isUserConfigDir() helper to detect user config directory
- Update resolveTargetDir() to return 'user-config' source
- Skip opencode.json creation in user-config dir (uses config.json)
- Skip duplicate scan in discoverPlugins() when targetDir is user-config

Author: wagnert

bin/opencode-link.js

@@ -102,9 +102,29 @@ function formatPluginLabel(descriptor) {
 
 // Target directory for linking (set in main() after argument parsing)
 let TARGET_DIR = null;
+let TARGET_SOURCE = null;
 let PLUGINS = null;
 let CONTENT_TYPES = null;
 
+/**
+ * Gets the OpenCode user config directory path.
+ * 
+ * @returns {string} Path to ~/.config/opencode
+ */
+function getUserConfigDir() {
+  return path.join(os.homedir(), '.config', 'opencode');
+}
+
+/**
+ * Checks if the given directory is the OpenCode user config directory.
+ * 
+ * @param {string} dir - Directory to check
+ * @returns {boolean} True if dir is ~/.config/opencode
+ */
+function isUserConfigDir(dir) {
+  return path.resolve(dir) === getUserConfigDir();
+}
+
 /**
  * Searches for opencode.json starting from current directory and going up.
  */
@@ -124,15 +144,30 @@ function findOpencodeConfig() {
 
 /**
  * Resolves the target directory for linking.
+ * 
+ * Detection order:
+ * 1. CLI --target-dir flag
+ * 2. OpenCode user config directory (~/.config/opencode)
+ * 3. Directory with opencode.json (search upwards)
+ * 4. .opencode subdirectory
+ * 5. Default: {cwd}/.opencode
  */
 function resolveTargetDir(cliTargetDir) {
   if (cliTargetDir) {
+    const resolved = path.resolve(process.cwd(), cliTargetDir);
     return {
-      targetDir: path.resolve(process.cwd(), cliTargetDir),
-      source: 'cli',
+      targetDir: resolved,
+      source: isUserConfigDir(resolved) ? 'user-config' : 'cli',
     };
   }
 
+  const cwd = process.cwd();
+
+  // Check if we're in the OpenCode user config directory
+  if (isUserConfigDir(cwd)) {
+    return { targetDir: cwd, source: 'user-config' };
+  }
+
   const configDir = findOpencodeConfig();
   if (configDir) {
     return {
@@ -141,8 +176,6 @@ function resolveTargetDir(cliTargetDir) {
     };
   }
 
-  const cwd = process.cwd();
-
   // Check if we're already in a .opencode directory
   if (path.basename(cwd) === '.opencode') {
     return { targetDir: cwd, source: 'auto' };
@@ -199,15 +232,17 @@ function ensureDirectoryStructure() {
     }
   }
 
-  // Ensure opencode.json exists
-  const configPath = path.join(TARGET_DIR, 'opencode.json');
-  if (!fs.existsSync(configPath)) {
-    const defaultConfig = {
-      $schema: 'https://opencode.ai/config.json',
-      instructions: ['guideline/*.md'],
-    };
-    fs.writeFileSync(configPath, JSON.stringify(defaultConfig, null, 2) + '\n');
-    logSuccess('opencode.json created');
+  // Ensure opencode.json exists (skip for user-config directory which uses config.json)
+  if (TARGET_SOURCE !== 'user-config') {
+    const configPath = path.join(TARGET_DIR, 'opencode.json');
+    if (!fs.existsSync(configPath)) {
+      const defaultConfig = {
+        $schema: 'https://opencode.ai/config.json',
+        instructions: ['guideline/*.md'],
+      };
+      fs.writeFileSync(configPath, JSON.stringify(defaultConfig, null, 2) + '\n');
+      logSuccess('opencode.json created');
+    }
   }
 }
 
@@ -629,16 +664,19 @@ async function main() {
   // Resolve target directory
   const { targetDir, source } = resolveTargetDir(cliTargetDir);
   TARGET_DIR = targetDir;
+  TARGET_SOURCE = source;
 
-  // Discover plugins (global + local)
+  // Discover plugins
   PLUGINS = discoverPlugins(TARGET_DIR);
   CONTENT_TYPES = getContentTypes(PLUGINS);
 
   log('\nOpenCode Plugin Linker', 'bright');
   log('='.repeat(50), 'gray');
 
   // Show target directory info
-  if (source === 'cli') {
+  if (source === 'user-config') {
+    log(`Target: ${TARGET_DIR} (user config directory)`, 'cyan');
+  } else if (source === 'cli') {
     log(`Target: ${TARGET_DIR} (from --target-dir)`, 'cyan');
   } else if (source === 'auto') {
     log(`Target: ${TARGET_DIR} (auto-detected opencode.json)`, 'cyan');

lib/discovery.js

@@ -31,23 +31,33 @@ function getUserConfigDir() {
  * 1. User config: ~/.config/opencode/node_modules/
  * 2. Local: {targetDir}/node_modules/
  * 
+ * If targetDir is the user config directory (~/.config/opencode), only local
+ * is scanned to avoid duplicate scanning of the same directory.
+ * 
  * @param {string} targetDir - The .opencode directory (e.g., /project/.opencode)
  * @returns {Map<string, PluginDescriptor>} Map of plugin name to descriptor
  */
 export function discoverPlugins(targetDir) {
   const userConfigDir = getUserConfigDir();
+  const localNodeModules = path.join(targetDir, 'node_modules');
 
   // Scan all locations (order matters: last wins)
   const allPlugins = new Map();
 
-  // 1. User config (lower priority)
-  const userPlugins = scanLocation(userConfigDir, 'user');
-  for (const [name, descriptor] of userPlugins.entries()) {
-    allPlugins.set(name, descriptor);
+  // Check if local === user-config (when running from ~/.config/opencode)
+  const isUserConfigTarget = path.resolve(localNodeModules) === path.resolve(userConfigDir);
+  
+  // 1. User config (lower priority) - skip if same as local
+  if (!isUserConfigTarget) {
+    const userPlugins = scanLocation(userConfigDir, 'user');
+    for (const [name, descriptor] of userPlugins.entries()) {
+      allPlugins.set(name, descriptor);
+    }
   }
 
-  // 2. Local (highest priority)
-  const localPlugins = scanLocation(path.join(targetDir, 'node_modules'), 'local');
+  // 2. Local (highest priority) - labeled as 'user' if it's the user-config dir
+  const localLabel = isUserConfigTarget ? 'user' : 'local';
+  const localPlugins = scanLocation(localNodeModules, localLabel);
   for (const [name, descriptor] of localPlugins.entries()) {
     if (allPlugins.has(name)) {
       console.log(`  ⚠️  Plugin "${name}" found in local, overrides user`);