Add AGENTS.md support for project instructions (#142)

Read AGENTS.md from project root and pass its content to the Claude SDK
via systemPrompt append, and include it in Ollama offline context. This
allows users who maintain AGENTS.md files in their projects to have those
instructions automatically loaded into chat sessions.

Co-authored-by: Claude <noreply@anthropic.com>

Author: 1code-async[bot]

README.md

@@ -19,7 +19,7 @@ By [21st.dev](https://21st.dev) team
 | **Integrated Terminal** | ✅ | ❌ |
 | **Plan Mode** | ✅ | ✅ |
 | **MCP Support** | ✅ | ✅ |
-| **Memory (CLAUDE.md)** | ✅ | ✅ |
+| **Memory (CLAUDE.md & AGENTS.md)** | ✅ | ✅ |
 | **Skills & Slash Commands** | ✅ | ✅ |
 | **Custom Subagents** | ✅ | ✅ |
 | **Subscription & API Key Support** | ✅ | ✅ |

src/main/lib/trpc/routers/claude.ts

@@ -979,6 +979,20 @@ export const claudeRouter = router({
               })
             }
 
+            // Read AGENTS.md from project root if it exists
+            let agentsMdContent: string | undefined
+            try {
+              const agentsMdPath = path.join(input.cwd, "AGENTS.md")
+              agentsMdContent = await fs.readFile(agentsMdPath, "utf-8")
+              if (agentsMdContent.trim()) {
+                console.log(`[claude] Found AGENTS.md at ${agentsMdPath} (${agentsMdContent.length} chars)`)
+              } else {
+                agentsMdContent = undefined
+              }
+            } catch {
+              // AGENTS.md doesn't exist or can't be read - that's fine
+            }
+
             // For Ollama: embed context AND history directly in prompt
             // Ollama doesn't have server-side sessions, so we must include full history
             let finalQueryPrompt: string | AsyncIterable<any> = prompt
@@ -1076,7 +1090,11 @@ IMPORTANT: When using tools, use these EXACT parameter names:
 
 When asked about the project, use Glob to find files and Read to examine them.
 Be concise and helpful.
-[/CONTEXT]
+[/CONTEXT]${agentsMdContent ? `
+
+[AGENTS.MD]
+${agentsMdContent}
+[/AGENTS.MD]` : ''}
 
 ${historyText}[CURRENT REQUEST]
 ${prompt}
@@ -1086,10 +1104,17 @@ ${prompt}
             }
 
             // System prompt config - use preset for both Claude and Ollama
-            const systemPromptConfig = {
-              type: "preset" as const,
-              preset: "claude_code" as const,
-            }
+            // If AGENTS.md exists, append its content to the system prompt
+            const systemPromptConfig = agentsMdContent
+              ? {
+                  type: "preset" as const,
+                  preset: "claude_code" as const,
+                  append: `\n\n# AGENTS.md\nThe following are the project's AGENTS.md instructions:\n\n${agentsMdContent}`,
+                }
+              : {
+                  type: "preset" as const,
+                  preset: "claude_code" as const,
+                }
 
             const queryOptions = {
               prompt: finalQueryPrompt,