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>

tsconfig.json

@@ -0,0 +1,56 @@
+{
+  // Visit https://aka.ms/tsconfig to read more about this file
+  "compilerOptions": {
+    // File Layout
+    "rootDir": "./src",
+    "outDir": "./dist",
+
+    // Environment Settings
+    // See also https://aka.ms/tsconfig/module
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    
+    "target": "es2022",
+    "lib": ["es2022"],
+    
+    "types": ["node"],
+    // For nodejs:
+    // "lib": ["esnext"],
+    // "types": ["node"],
+    // and npm install -D @types/node
+
+    "resolveJsonModule": true,
+    "forceConsistentCasingInFileNames": true,
+    "noEmitOnError": true,
+    
+    // Other Outputs
+    "sourceMap": true,
+    "declaration": true,
+    "declarationMap": true,
+
+    // Stricter Typechecking Options
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+
+    // Style Options
+    // "noImplicitReturns": true,
+    // "noImplicitOverride": true,
+    // "noUnusedLocals": true,
+    // "noUnusedParameters": true,
+    // "noFallthroughCasesInSwitch": true,
+    // "noPropertyAccessFromIndexSignature": true,
+
+    // Recommended Options
+    "strict": true,
+    "noUncheckedSideEffectImports": true,
+    "skipLibCheck": true,
+  },
+  "include": [
+    "src/**/*"
+  ],
+  "exclude": [
+    "node_modules",
+    "dist",
+    "mcp-server"
+  ]
+}