Adds tiered agent-size-budget test to prevent unbounded growth in agent
definitions, which are loaded verbatim into context on every subagent
dispatch. Extracts two duplicated blocks (mandatory-initial-read,
project-skills-discovery) to shared references under
get-shit-done/references/ and migrates the 5 top agents (planner,
executor, debugger, verifier, phase-researcher) to @file includes.
Also fixes two broken relative @planner-source-audit.md references in
gsd-planner.md that silently disabled the planner's source audit
discipline.
Closes#2361
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
c5e77c8809