feat: implement context file loading system for agent prompts

- Introduced a new utility function `loadContextFiles` to load project-specific context files from the `.automaker/context/` directory, enhancing agent prompts with project rules and guidelines.
- Updated `AgentService` and `AutoModeService` to utilize the new context loading functionality, combining context prompts with existing system prompts for improved agent performance.
- Added comprehensive documentation on the context files system, including usage examples and metadata structure, to facilitate better understanding and implementation.
- Removed redundant context loading logic from `AutoModeService`, streamlining the codebase.

These changes aim to improve the agent's contextual awareness and adherence to project-specific conventions.

docs/context-files-pattern.md

@@ -0,0 +1,170 @@
+# Context Files System
+
+This document describes how context files work in Automaker and how to use them in agent prompts.
+
+## Overview
+
+Context files are user-defined documents stored in `.automaker/context/` that provide project-specific rules, conventions, and guidelines for AI agents. They are automatically loaded and prepended to agent prompts.
+
+## Directory Structure
+
+```
+{projectPath}/.automaker/context/
+├── CLAUDE.md              # Project rules and conventions
+├── CODE_QUALITY.md        # Code quality guidelines
+├── context-metadata.json  # File descriptions
+└── ... (any .md or .txt files)
+```
+
+## Metadata
+
+File descriptions are stored in `context-metadata.json`:
+
+```json
+{
+  "files": {
+    "CLAUDE.md": {
+      "description": "Project-specific rules including package manager, commit conventions, and architectural patterns"
+    },
+    "CODE_QUALITY.md": {
+      "description": "Code quality standards, testing requirements, and linting rules"
+    }
+  }
+}
+```
+
+## Shared Utility
+
+The `loadContextFiles` function from `@automaker/utils` provides a unified way to load context files:
+
+```typescript
+import { loadContextFiles } from '@automaker/utils';
+
+// Load context files from a project
+const { formattedPrompt, files } = await loadContextFiles({
+  projectPath: '/path/to/project',
+  // Optional: inject custom fs module for secure operations
+  fsModule: secureFs,
+});
+
+// formattedPrompt contains the formatted system prompt
+// files contains metadata about each loaded file
+```
+
+### Return Value
+
+```typescript
+interface ContextFilesResult {
+  files: ContextFileInfo[]; // Individual file info
+  formattedPrompt: string; // Formatted prompt ready to use
+}
+
+interface ContextFileInfo {
+  name: string; // File name (e.g., "CLAUDE.md")
+  path: string; // Full path to file
+  content: string; // File contents
+  description?: string; // From metadata (explains when/why to use)
+}
+```
+
+## Usage in Services
+
+### Auto-Mode Service (Feature Execution)
+
+```typescript
+import { loadContextFiles } from '@automaker/utils';
+import * as secureFs from '../lib/secure-fs.js';
+
+// In executeFeature() or followUpFeature()
+const { formattedPrompt: contextFilesPrompt } = await loadContextFiles({
+  projectPath,
+  fsModule: secureFs as Parameters<typeof loadContextFiles>[0]['fsModule'],
+});
+
+// Pass as system prompt
+await this.runAgent(workDir, featureId, prompt, abortController, projectPath, imagePaths, model, {
+  projectPath,
+  systemPrompt: contextFilesPrompt || undefined,
+});
+```
+
+### Agent Service (Chat Sessions)
+
+```typescript
+import { loadContextFiles } from '@automaker/utils';
+import * as secureFs from '../lib/secure-fs.js';
+
+// In sendMessage()
+const { formattedPrompt: contextFilesPrompt } = await loadContextFiles({
+  projectPath: effectiveWorkDir,
+  fsModule: secureFs as Parameters<typeof loadContextFiles>[0]['fsModule'],
+});
+
+// Combine with base system prompt
+const combinedSystemPrompt = contextFilesPrompt
+  ? `${contextFilesPrompt}\n\n${baseSystemPrompt}`
+  : baseSystemPrompt;
+```
+
+## Formatted Prompt Structure
+
+The formatted prompt includes:
+
+1. **Header** - Emphasizes that these are project-specific rules
+2. **File Entries** - Each file with:
+   - File name
+   - Full path (for agents to read more if needed)
+   - Purpose/description (from metadata)
+   - Full file content
+3. **Reminder** - Reinforces that agents must follow the conventions
+
+Example output:
+
+```markdown
+# Project Context Files
+
+The following context files provide project-specific rules, conventions, and guidelines.
+Each file serves a specific purpose - use the description to understand when to reference it.
+If you need more details about a context file, you can read the full file at the path provided.
+
+**IMPORTANT**: You MUST follow the rules and conventions specified in these files.
+
+- Follow ALL commands exactly as shown (e.g., if the project uses `pnpm`, NEVER use `npm` or `npx`)
+- Follow ALL coding conventions, commit message formats, and architectural patterns specified
+- Reference these rules before running ANY shell commands or making commits
+
+---
+
+## CLAUDE.md
+
+**Path:** `/path/to/project/.automaker/context/CLAUDE.md`
+**Purpose:** Project-specific rules including package manager, commit conventions, and architectural patterns
+
+[File content here]
+
+---
+
+## CODE_QUALITY.md
+
+**Path:** `/path/to/project/.automaker/context/CODE_QUALITY.md`
+**Purpose:** Code quality standards, testing requirements, and linting rules
+
+[File content here]
+
+---
+
+**REMINDER**: Before taking any action, verify you are following the conventions specified above.
+```
+
+## Best Practices
+
+1. **Add descriptions** - Always add descriptions to `context-metadata.json` so agents understand when to reference each file
+2. **Be specific** - Context files should contain concrete rules, not general guidelines
+3. **Include examples** - Show correct command usage, commit formats, etc.
+4. **Keep focused** - Each file should have a single purpose
+
+## File Locations
+
+- **Shared Utility**: `libs/utils/src/context-loader.ts`
+- **Auto-Mode Service**: `apps/server/src/services/auto-mode-service.ts`
+- **Agent Service**: `apps/server/src/services/agent-service.ts`