PERF.md: the prefix budget table says the caps the gate enforces

PERF.md

@@ -1295,8 +1295,8 @@ anything, which is #576's shape.
 
 | | weighed | cap | target owed |
 | --- | --- | --- | --- |
-| full (`fixedPrefixBudget`) | **53,141** | 53,141 | 48,000, **5,141** over |
-| lean (`leanPrefixBudget`) | **44,916** | 44,916 | 31,500, **13,416** over |
+| full (`fixedPrefixBudget`) | **53,291** | 53,291 | 48,000, **5,291** over |
+| lean (`leanPrefixBudget`) | **45,066** | 45,066 | 31,500, **13,566** over |
 
 **The cap is the target plus a dated waiver, and a waiver only ever shrinks.**
 `fixedPrefixTarget` and `leanPrefixTarget` are what each arm is supposed to be;

docs/changes/unreleased/1033-perf-prefix-table.md

@@ -0,0 +1,17 @@
+---
+kind: fixed
+title: PERF.md's prefix budget table reads the caps the gate enforces
+pr: 1033
+# Optional. Which part of the repository this touches, so a reader can skip it.
+# One or more of: build, chat, docs, engine, remote, resident
+surface: [docs]
+# Optional, and the reason this file exists. Every statement that WAS true and is
+# not any more, written whole: what it was, and what it is now. A model reading
+# this has to be able to check its own memory against it, so "branch names" is
+# useless and "the trunk was chat-v3-task and no longer exists; work goes to dev"
+# is the whole point. Leave the list empty if nothing anybody believed changed.
+invalidates:
+  - "PERF.md's prefix budget table said 53,141 (full) and 44,916 (lean), over the targets by 5,141 and 13,416; the gate has enforced 53,291 and 45,066 since the waivers moved +150, and the table now says so."
+---
+
+The waivers were raised in code with the reason beside them and the table was never opened. A cap that changes changes the doc in the same commit; this is that commit, late.