2.1.0: ship the unbenchmarked read-ahead hint off by default

[ShugokiFable]

Why

A real 1.6.1170 session logged:

Stats snapshot: opens=26162 patched=6481 no_buffering_stripped=0 in_scope_safety_gated=0 warm_read=0 MB

no_buffering_stripped=0 means the engine never set FILE_FLAG_NO_BUFFERING on that runtime, so the cache-restoring half of this plugin had nothing to do. That left FILE_FLAG_RANDOM_ACCESS as the only live effect the plugin had - a caching hint that disables the cache manager's read-ahead, where the FILE_FLAG_SEQUENTIAL_SCAN it displaces enlarges it. It has never been benchmarked as a win, and it was being applied to thousands of archive opens per minute.

An unmeasured change at that rate is not a safe default.

What changed

• Safe now ships bPreferRandomAccessOnArchives=0.
• Experimental keeps it on so the two profiles can be A/B compared on the same save and route.
• Minimal is now behaviourally identical to Safe; documented rather than removed so existing installs keep working.
• Log statistics snapshot states in plain words when the plugin made no difference on your runtime.
• README, FOMOD descriptions and CHANGELOG updated to match.

What did not change

Hook scope, safety gates, archive eligibility rules, and the DirectStorage backend (still disabled and not shipped).

Validation

• python tools/validate_rc.py -> VALIDATION PASS
• Local VS2026 build OK (363,520 bytes); release artifact will be the CI build from tag v2.1.0.

🤖 Generated with Claude Code