Fixes a regression introduced in v0.25.2 where PostgreSQL IN clause
placeholders were not properly incremented, causing all parameters to
use the same placeholder index (e.g., $1, $1, $1 instead of $1, $2, $3).

This bug affected:
- ListReactions (ContentIDList) - caused "failed to list reactions" errors
- ListAttachments (MemoIDList)
- ListMemos (IDList and UIDList)

The fix combines placeholder generation and argument appending into a
single loop to ensure proper incrementing.

Fixes #5188

🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>