feat(mcp): update formatters for rich search results

[prosdev]

Summary

Implements #70 - Fourth sub-issue of Epic #66 (Richer Search Results)

Changes

packages/mcp-server/src/formatters/types.ts

• Added includeSnippets?: boolean
• Added includeImports?: boolean
• Added maxSnippetLines?: number

packages/mcp-server/src/formatters/compact-formatter.ts

• Snippets/imports off by default (token efficient)
• Added formatHeader(), truncateSnippet(), indentText() helpers
• Max 5 imports shown with "..." truncation
• Updated estimateTokens() for new content

packages/mcp-server/src/formatters/verbose-formatter.ts

• Snippets/imports on by default (full context)
• Shows location with line range (e.g., file.ts:45-67)
• Added same helper methods
• Updated estimateTokens() for new content

packages/mcp-server/src/formatters/__tests__/formatters.test.ts

• Added 17 new tests for snippet/import formatting

Example Output

Compact (with options enabled)

1. [85%] function: handleAuth (src/auth/handler.ts:45)
   export async function handleAuth(req: Request) {
     const token = extractToken(req);
     // ... 15 more lines
   }
   Imports: ./service, ../utils/jwt, express

Verbose (default)

1. [Score: 85.0%] function: handleAuth
  Location: src/auth/handler.ts:45-67
  Signature: async handleAuth(req: Request): Promise<Response>
  Imports: ./service, ../utils/jwt, express
  Metadata: language: typescript, exported: true, lines: 23
  Code:
    export async function handleAuth(req: Request) {
      const token = extractToken(req);
      // ... 15 more lines
    }

Testing

• ✅ 1282 tests passing (17 new)
• ✅ TypeScript compiles without errors
• ✅ Biome linting passes

Related Issues

• Closes Update MCP formatters for rich search results #70
• Part of Epic Epic: Richer Search Results #66