Before each model call, Elcro builds messages from:

1. System prompt (mode, workspace paths, open files, tool catalog, MCP list).
2. .elcrorules / .voidrules and Settings AI instructions.
3. Skills, commands, and subagents from .elcro/.
4. Thread history (user, assistant, tool results).
5. Explicit @ attachments.

Long threads are trimmed with weighting that prefers keeping system + recent user turns.