refactor: deduplicate prompt templates with shared content system

Implemented @include() directive system to eliminate ~800 lines of duplicated content across 10 specialist prompt files. All prompt-related content now consolidated under prompts/ directory for better maintainability.

Changes:
- Added processIncludes() to prompt-manager.js for generic @include() support
- Created prompts/shared/ with 5 reusable template files
- Refactored all 10 specialist prompts to use @include() for common sections
- Moved login_instructions.txt to prompts/shared/ (deleted login_resources/)
- Updated CLAUDE.md to reflect new structure

Impact: -137 net lines, zero breaking changes, infinitely scalable for future shared content.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/prompts/prompt-manager.js

@@ -7,7 +7,7 @@ import { MCP_AGENT_MAPPING } from '../constants.js';
 async function buildLoginInstructions(authentication) {
   try {
     // Load the login instructions template
-    const loginInstructionsPath = path.join(import.meta.dirname, '..', '..', 'login_resources', 'login_instructions.txt');
+    const loginInstructionsPath = path.join(import.meta.dirname, '..', '..', 'prompts', 'shared', 'login-instructions.txt');
 
     if (!await fs.pathExists(loginInstructionsPath)) {
       throw new PentestError(
@@ -84,6 +84,27 @@ async function buildLoginInstructions(authentication) {
   }
 }
 
+// Pure function: Process @include() directives
+async function processIncludes(content, baseDir) {
+  const includeRegex = /@include\(([^)]+)\)/g;
+  // Use a Promise.all to handle all includes concurrently
+  const replacements = await Promise.all(
+    Array.from(content.matchAll(includeRegex)).map(async (match) => {
+      const includePath = path.join(baseDir, match[1]);
+      const sharedContent = await fs.readFile(includePath, 'utf8');
+      return {
+        placeholder: match[0],
+        content: sharedContent,
+      };
+    })
+  );
+
+  for (const replacement of replacements) {
+    content = content.replace(replacement.placeholder, replacement.content);
+  }
+  return content;
+}
+
 // Pure function: Variable interpolation
 async function interpolateVariables(template, variables, config = null) {
   try {
@@ -198,7 +219,11 @@ export async function loadPrompt(promptName, variables, config = null, pipelineT
       console.log(chalk.yellow(`    🎭 Unknown agent ${promptName}, using fallback → ${enhancedVariables.MCP_SERVER}`));
     }
 
-    const template = await fs.readFile(promptPath, 'utf8');
+    let template = await fs.readFile(promptPath, 'utf8');
+
+    // Pre-process the template to handle @include directives
+    template = await processIncludes(template, promptsDir);
+
     return await interpolateVariables(template, enhancedVariables, config);
   } catch (error) {
     if (error instanceof PentestError) {