fix(agents): address cubic review findings on agent loader

- Case-insensitive .md extension stripping for agent name extraction
- Resolve project agent_definitions paths relative to config dir (.opencode/)
- Use getOpenCodeConfigDir() to respect OPENCODE_CONFIG_DIR/XDG_CONFIG_HOME
- First-write-wins semantics for both inline and definition-file agents
  so project-level agents always take precedence over global-level

src/features/claude-code-agent-loader/agent-definitions-loader.test.ts

@@ -82,6 +82,22 @@ Prompt.`
       expect(result?.config.prompt).toBe("Prompt.")
     })
 
+    test("strips .MD extension case-insensitively for agent name", () => {
+      const filePath = join(tempDir, "UpperCase.MD")
+      const content = `---
+description: Mixed case extension
+---
+
+Prompt content.`
+
+      writeFileSync(filePath, content, "utf-8")
+
+      const result = parseMarkdownAgentFile(filePath, "definition-file")
+
+      expect(result).not.toBeNull()
+      expect(result?.name).toBe("UpperCase")
+    })
+
     test("defaults mode to subagent when not specified", () => {
       const filePath = join(tempDir, "no-mode.md")
       const content = `---

src/features/claude-code-agent-loader/agent-definitions-loader.ts

@@ -28,7 +28,8 @@ export function parseMarkdownAgentFile(filePath: string, scope: AgentScope): Loa
     const content = readFileSync(filePath, "utf-8")
     const { data, body } = parseFrontmatter<AgentFrontmatter>(content)
 
-    const agentName = basename(filePath, ".md")
+    const fileName = basename(filePath)
+    const agentName = fileName.replace(/\.md$/i, "")
     const name = data.name || agentName
     const originalDescription = data.description || ""
 

src/features/claude-code-agent-loader/opencode-config-agents-reader.test.ts

@@ -124,7 +124,7 @@ describe("readOpencodeConfigAgents", () => {
     const opencodeDir = path.join(tempDir, ".opencode")
     fs.mkdirSync(opencodeDir, { recursive: true })
 
-    const agentDefFile = path.join(tempDir, "agents.json")
+    const agentDefFile = path.join(opencodeDir, "agents.json")
     fs.writeFileSync(
       agentDefFile,
       JSON.stringify({
@@ -146,7 +146,7 @@ describe("readOpencodeConfigAgents", () => {
 
     if (Object.keys(result).length > 0) {
       expect(result).toHaveProperty("definition-agent")
-      expect(result["definition-agent"].description).toContain("definition-file")
+      expect(result["definition-agent"].description).toContain("From definition file")
     }
 
     fs.rmSync(tempDir, { recursive: true })
@@ -157,7 +157,7 @@ describe("readOpencodeConfigAgents", () => {
     const opencodeDir = path.join(tempDir, ".opencode")
     fs.mkdirSync(opencodeDir, { recursive: true })
 
-    const agentDefFile = path.join(tempDir, "agents.json")
+    const agentDefFile = path.join(opencodeDir, "agents.json")
     fs.writeFileSync(
       agentDefFile,
       JSON.stringify({
@@ -288,7 +288,7 @@ describe("readOpencodeConfigAgents", () => {
     const opencodeDir = path.join(tempDir, ".opencode")
     fs.mkdirSync(opencodeDir, { recursive: true })
 
-    const agentDef1 = path.join(tempDir, "agents1.json")
+    const agentDef1 = path.join(opencodeDir, "agents1.json")
     fs.writeFileSync(
       agentDef1,
       JSON.stringify({
@@ -298,7 +298,7 @@ describe("readOpencodeConfigAgents", () => {
       })
     )
 
-    const agentDef2 = path.join(tempDir, "agents2.json")
+    const agentDef2 = path.join(opencodeDir, "agents2.json")
     fs.writeFileSync(
       agentDef2,
       JSON.stringify({

src/features/claude-code-agent-loader/opencode-config-agents-reader.ts

@@ -1,7 +1,7 @@
 import * as fs from "node:fs"
-import * as os from "node:os"
 import * as path from "node:path"
 
+import { getOpenCodeConfigDir } from "../../shared/opencode-config-dir"
 import { parseJsoncSafe } from "../../shared/jsonc-parser"
 import { loadAgentDefinitions } from "./agent-definitions-loader"
 import { mapClaudeModelToOpenCode } from "./claude-model-mapper"
@@ -13,27 +13,15 @@ interface OpencodeConfigWithAgents {
   agent_definitions?: string | string[]
 }
 
-function getWindowsAppdataDir(): string | null {
-  return process.env.APPDATA || null
-}
-
 function getConfigPaths(directory: string): string[] {
-  const crossPlatformDir = path.join(os.homedir(), ".config")
+  const globalConfigDir = getOpenCodeConfigDir({ binary: "opencode" })
   const paths = [
     path.join(directory, ".opencode", "opencode.json"),
     path.join(directory, ".opencode", "opencode.jsonc"),
-    path.join(crossPlatformDir, "opencode", "opencode.json"),
+    path.join(globalConfigDir, "opencode.json"),
-    path.join(crossPlatformDir, "opencode", "opencode.jsonc"),
+    path.join(globalConfigDir, "opencode.jsonc"),
   ]
 
-  if (process.platform === "win32") {
-    const appdataDir = getWindowsAppdataDir()
-    if (appdataDir) {
-      paths.push(path.join(appdataDir, "opencode", "opencode.json"))
-      paths.push(path.join(appdataDir, "opencode", "opencode.jsonc"))
-    }
-  }
-
   return paths
 }
 
@@ -108,6 +96,7 @@ export function readOpencodeConfigAgents(directory: string): Record<string, Clau
 
       if (agentsToLoad && typeof agentsToLoad === "object") {
         for (const [agentName, agentData] of Object.entries(agentsToLoad)) {
+          if (agentName in result) continue
           const converted = convertInlineAgent(agentData)
           if (converted) {
             result[agentName] = converted

src/plugin-config.ts

@@ -278,7 +278,7 @@ export function loadPluginConfig(
   if (projectConfig?.agent_definitions) {
     projectConfig.agent_definitions = resolveAgentDefinitionPaths(
       projectConfig.agent_definitions,
-      directory,
+      projectBasePath,
       directory
     )
   }