feat: typescript migration (#40)

* chore: initialize TypeScript configuration and build setup

- Add tsconfig.json for root and mcp-server with strict type checking
- Install typescript and @types/node as devDependencies
- Add npm build script for TypeScript compilation
- Update main entrypoint to compiled dist/shannon.js
- Update Dockerfile to build TypeScript before running
- Configure output directory and module resolution for Node.js

* refactor: migrate codebase from JavaScript to TypeScript

- Convert all 37 JavaScript files to TypeScript (.js -> .ts)
- Add type definitions in src/types/ for agents, config, errors, session
- Update mcp-server with proper TypeScript types
- Move entry point from shannon.mjs to src/shannon.ts
- Update tsconfig.json with rootDir: "./src" for cleaner dist output
- Update Dockerfile to build TypeScript before runtime
- Update package.json paths to use compiled dist/shannon.js

No runtime behavior changes - pure type safety migration.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* docs: update CLI references from ./shannon.mjs to shannon

- Update help text in src/cli/ui.ts
- Update usage examples in src/cli/command-handler.ts
- Update setup message in src/shannon.ts
- Update CLAUDE.md documentation with TypeScript file structure
- Replace all ./shannon.mjs references with shannon command

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* chore: remove unnecessary eslint-disable comments

ESLint is not configured in this project, making these comments redundant.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/cli/input-validator.ts

@@ -0,0 +1,59 @@
+// Copyright (C) 2025 Keygraph, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License version 3
+// as published by the Free Software Foundation.
+
+import { fs, path } from 'zx';
+
+interface ValidationResult {
+  valid: boolean;
+  error?: string;
+  path?: string;
+}
+
+// Helper function: Validate web URL
+export function validateWebUrl(url: string): ValidationResult {
+  try {
+    const parsed = new URL(url);
+    if (!['http:', 'https:'].includes(parsed.protocol)) {
+      return { valid: false, error: 'Web URL must use HTTP or HTTPS protocol' };
+    }
+    if (!parsed.hostname) {
+      return { valid: false, error: 'Web URL must have a valid hostname' };
+    }
+    return { valid: true };
+  } catch {
+    return { valid: false, error: 'Invalid web URL format' };
+  }
+}
+
+// Helper function: Validate local repository path
+export async function validateRepoPath(repoPath: string): Promise<ValidationResult> {
+  try {
+    // Check if path exists
+    if (!(await fs.pathExists(repoPath))) {
+      return { valid: false, error: 'Repository path does not exist' };
+    }
+
+    // Check if it's a directory
+    const stats = await fs.stat(repoPath);
+    if (!stats.isDirectory()) {
+      return { valid: false, error: 'Repository path must be a directory' };
+    }
+
+    // Check if it's readable
+    try {
+      await fs.access(repoPath, fs.constants.R_OK);
+    } catch {
+      return { valid: false, error: 'Repository path is not readable' };
+    }
+
+    // Convert to absolute path
+    const absolutePath = path.resolve(repoPath);
+    return { valid: true, path: absolutePath };
+  } catch (error) {
+    const errMsg = error instanceof Error ? error.message : String(error);
+    return { valid: false, error: `Invalid repository path: ${errMsg}` };
+  }
+}