CLAUDE.md: add convention — correct (+ sweep) context-system errors when ground truth contradicts them

The context system is a reconstruction; some claims are wrong. When the decomp/binary/engine
source contradicts a context/glossary/docs claim, FIX it + grep-sweep the same claim across the
other topic files + re-run checkctx.py -- don't just work around it. Archetype cited: the 0xBD3
'gates the valve/message routes' correction from this session.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -106,6 +106,13 @@ Tag individual claims (not sections) inline: `[T1]`, `[T2]`, … A claim inherit
 - **A `+0x128`-style owner offset is the subsystem ROSTER, not the segment table.**
 - **RULE: no stand-ins** — read the decomp; a gap is an unfilled stub.
 - **Keep the knowledge base current** — new durable findings → `context/*.md` (+ `docs/` for detail).
+- **Correct errors when you find them.** The context system is a reconstruction — some claims are
+  wrong. When the decomp / binary / engine source (ground truth) CONTRADICTS a claim in `context/*.md`
+  (or the glossary/`docs/`), FIX it — don't just work around it. Then **grep the other topic files for
+  the same wrong claim and sweep it** (a mistaken belief is often repeated across files), re-run
+  `scratchpad/checkctx.py`, and note the correction. Prefer this over silently distrusting a file.
+  (Archetype: the `0xBD3` "gates the valve/message routes" claim was wrong — 0xBD3 is a damage/explosion
+  hub; the real gate is the owning `BTPlayer` at `mech+0x190`. Verified from the decomp, then swept.)
 
 ## DO NOT
 - Present T3/T4 claims as established without flagging the tier.