Add AI agent detection to auto-switch to raw output

[pushpak1300]

This pull request adds AI agent detection that automatically switches PHPStan to raw error format and suppresses progress bar output when executed within Claude Code, Cursor, Gemini CLI, Codex, OpenCode, Augment, Replit, or Devin.

Why:

The default PHPStan output is designed for humans - colorful tables, progress bars with animations, and formatted summaries. AI agents need something different: minimal output that saves context window and reduces token cost, unambiguous error details with file paths and line numbers, and no progress bar animations that waste tokens on redraw noise.

Why raw format over JSON?

The raw format (file:line:message, one error per line) is significantly more token-efficient than JSON:

Scenario	JSON	Raw	Token Savings
3 errors / 2 files	~185 tokens (678 chars)	~95 tokens (295 chars)	~49%
0 errors	~18 tokens (62 chars)	0 tokens (empty)	100%

JSON carries structural overhead per error (repeated keys like "message", "line", "ignorable", "identifier", plus nesting and punctuation). The raw format eliminates all of this while preserving the essential information agents need: file path, line number, and error message.

How it works:

1. When Claude Code runs PHPStan, it sets the CLAUDECODE / CLAUDE_CODE environment variable
2. When Cursor runs PHPStan, it sets CURSOR_TRACE_ID / CURSOR_AGENT
3. Other agents set their own env vars (GEMINI_CLI, CODEX_SANDBOX, AI_AGENT, etc.)
4. PHPStan detects these and automatically:
   • Switches to raw format (one error per line as file:line:message)
   • Suppresses progress bar output entirely (equivalent to --no-progress)

Detection is inlined (simple getenv() calls) to avoid any external dependency and maintain compatibility with all PHP versions PHPStan supports.

Output example:

/app/src/Controller/UserController.php:42:Parameter #1 $id expects int, string given.
/app/src/Service/PaymentService.php:18:Call to an undefined method proccess().

Explicit --error-format=table or config errorFormat: table always takes priority over agent detection.

Changes:

• New AgentDetectedErrorFormatter class (follows CiDetectedErrorFormatter pattern) — delegates to RawErrorFormatter
• Modified AnalyseCommand to check for agents when no explicit format is set
• Modified ErrorsConsoleStyle to fully suppress progress bar for agents (no output at all, not just slower redraws)
• Added tests for agent detection and raw output

[phpstan-bot]

This pull request has been marked as ready for review.

[ondrejmirtes]

JSON is not good for LLM agents https://www.reddit.com/r/AI_Agents/comments/1p3kc7s/stop_burning_money_sending_json_to_your_agents/

[pushpak1300]

@ondrejmirtes Are you open for adding toon formatter ? happy to send the pr.

[ondrejmirtes]

try the existing raw formatter, it's pretty minimal and works well I think