fix: call command outputs raw text content instead of MCP envelope

[philschmid]

Fixes #25

Problem

The call command was outputting the full MCP protocol envelope:

{ "content": [{ "type": "text", "text": "..." }] }

This made it hard to pipe output to jq, grep, head, etc. without extracting .content[0].text.

Solution

Now outputs raw text content directly, restoring the v0.1.4 behavior.

Changes

• Use existing formatToolResult helper in call.ts
• Update SKILL.md examples (remove jq extraction patterns)
• Update CHANGELOG.md to reflect correct behavior
• Add e2e test to prevent regression

Before/After

# Before (v0.3.0)
$ mcp-cli call server/tool '{}'
{ "content": [{ "type": "text", "text": "[...]" }] }

# After
$ mcp-cli call server/tool '{}'
[...]  # Raw text, directly pipeable