automaton/tasks/fix-context-sizing/IMPLEMENTATION.md

Implementation: fix-context-sizing

Implements SPEC.md R1–R6. Files touched:

• scripts/vram_detect.py — R1 (double headroom), R2 (fake clamps), R3 (--loop-mode refuse), R4 (JSON fields)
• config.md — R5 (## Loop Role Models section)
• prompts/decompose.md — R6 (4k tier + 16k floor)
• tests/test_context_sizing.py — new tests

Approach

recommend_context rewritten so headroom is applied exactly once. main() reports honest numbers (no else 8/else 6 fallbacks). New --loop-mode CLI flag refuses zero-context-unknown and sub-16k available budget; non-loop callers keep prior behavior. JSON output exposes available_context_kb and loop_mode_eligible.

config.md gets a ## Loop Role Models section. decompose.md's context-budget table grows a 4k row and an explicit ≤ 16k: refuse floor statement.