feat(refs): base-instructions (Level 0→3)

[notque]

Summary

• Target: base-instructions agent
• Level before: 0 (no references directory)
• Level after: 3 (deep references with detection commands)

New Reference Files

• agents/base-instructions/references/communication-patterns.md (221 lines) — Failure mode catalog for agent output style: self-congratulation, narration before tool calls, difficulty inflation, hollow completions, excessive caveats. Each entry has grep/rg detection commands and before/after examples.
• agents/base-instructions/references/testing.md (172 lines) — Test scaffold and temporary file identification patterns. File category decision table, detection grep commands for orphaned debug scripts, one-off validation scripts, and unimplemented stubs. Cleanup guidance for task completion phase.

Agent Body Change

Added loading table to agents/base-instructions.md mapping task signals to the new reference files:

• "Writing progress updates, completing tasks" → communication-patterns.md
• "Creating temp files, scaffolds, debug scripts; cleanup phase" → testing.md

Validation Gate

Phase 2.5 passed — both references contain concrete, grep-detectable patterns with code examples and error-fix tables. Loading table entries correctly match signal keywords to file paths.

Audit Output

communication-patterns.md  221 lines  concrete=82  generic=4  code=Y  cmds=Y
testing.md                 172 lines  concrete=71  generic=0  code=Y  cmds=Y
Level: 0 → 3