feat: add HIDE_TOOL_FILE_MESSAGES env var to suppress file edit documents

[Paslestrange]

Summary

Adds a new HIDE_TOOL_FILE_MESSAGES configuration flag that prevents the bot from sending edit_*.txt and write_*.txt code file attachments to Telegram.

Motivation

When the bot edits or writes files, it currently sends every change as a .txt document to Telegram. For users working on larger tasks, this creates a lot of noise in the chat. This PR gives users an opt-in way to suppress those file-edit documents while still receiving all streaming text responses and pinned diff summaries.

Changes

• src/config.ts: Parse HIDE_TOOL_FILE_MESSAGES env var
• src/bot/index.ts: Skip enqueueFile in setOnToolFile when the flag is true
• .env.example: Document the new option
• README.md: Add the new env var to the configuration table
• tests/config.test.ts: Update tests to cover the new flag

Usage

HIDE_TOOL_FILE_MESSAGES=true

[Paslestrange]

Hi @grinev,

I've created this PR to reduce some noise in the chat. In my case the edits are causing a lot of messages, which bloat the notifications and the chat.

If you think this is helpful, please have a look :)

[grinev]

@Paslestrange thanks for PR. I've tested locally, I set HIDE_TOOL_FILE_MESSAGES=true, and I expected to see edit messages like ✏️ edit src\main\kotlin\ru\grinev\service\ChatService.kt (+8) but without file attachments. But I did't see any messages about file edits. That's not acceptable. Please change flag name to HIDE_FILE_CHANGES_ATTACHMENTS and if it is true, files with diffs won't be send, but you see edit/write/patch messages.

[grinev]

@Paslestrange I think I will do rework leves of progress later, so I will approve this