docs(cg-30): changelog entry + record the self-query probe flip honestly

The self-query allocation probe fixture's delivered-share gates now fail. The
cause is not the new bound: allocation is unchanged between arms (parse-run.mjs
32.3% vs 33.9% on main) and tools.ts delivers the same 8,282 chars in both. What
changed is that the incidental file now DELIVERS — on main its whole section was
cut by the hard-ceiling truncation, so the fixture passed on truncation luck.
Every file on this repo obeys the new bound (max 1.40x of spendable).

Recorded as `afterCG30` with that reasoning rather than tuning the bound to
restore the pass. The over-reservation it exposes is epic CG-24's subject.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/agent-eval/allocation-fixtures.json

@@ -4,7 +4,13 @@
     "explore budget allocation. Run them with `node scripts/agent-eval/probe-allocation.mjs`",
     "against a built dist/.",
     "",
-    "STATUS: BOTH FIXTURES PASS. CG-10 (relevance scoring) closed the RANKING half —",
+    "STATUS: payroll-go PASSES. self-query's delivered-share gates FAIL as of CG-30 —",
+    "see its `afterCG30` block: the allocated shares are unchanged, but bounding the",
+    "oversize-member overshoot stopped the hard ceiling from truncating away the",
+    "incidental file that had been over-RESERVED all along. The over-reservation is",
+    "epic CG-24's subject (a low-scoring file taking a top-file share), not CG-30's.",
+    "",
+    "CG-10 (relevance scoring) closed the RANKING half —",
     "nothing incidental reaches the envelope any more — and CG-12 (score-proportional",
     "allocation with a relative cliff) closed the BYTE SPLIT: each file's share is reserved",
     "before anything renders, and a file under 15% of the top weight gets no source at all,",
@@ -153,6 +159,17 @@
           "src/resolution/lru-cache.ts": 0.111
         },
         "verdict": "ALL GATES PASS. tools.ts takes 60.6% of the envelope, up from 18.5% at baseline and 32.9% after CG-10 — past the epic's >50% acceptance bar. The reversal is the whole point: memory-budget.ts no longer wins by being small enough to ship whole (it now clusters within its 3.1K reservation), and tools.ts is no longer clipped at maxCharsPerFile (11K reservation, ~3x the old flat cap). Exception to 'no previously-unclipped file becomes clipped': memory-budget.ts was unclipped-whole at 5,672 and is now clipped to its proportional share. That is the epic's own diagnosis of the bug, not a regression — it scored 18 against tools.ts's 58 and was taking the larger slice."
+      },
+      "afterCG30": {
+        "measuredOn": "2026-08-06",
+        "note": "23,688 delivered of 26,430 allocated, truncated at the 25,000 ceiling. Baseline (main) on the SAME index: 14,851 delivered of 25,221 allocated. tools.ts delivers 8,282 chars in BOTH arms — identical bytes; only the denominator moved.",
+        "delivered": {
+          "scripts/agent-eval/parse-run.mjs": 0.361,
+          "src/mcp/tools.ts": 0.35,
+          "src/mcp/explore-session-state.ts": 0.147,
+          "src/resolution/memory-budget.ts": 0.0
+        },
+        "verdict": "THREE GATES FAIL — and the cause is not the CG-30 bound. Allocation is unchanged between arms (parse-run.mjs 32.3% here vs 33.9% on main); what changed is that it now DELIVERS. On main its whole 8,548-char section was cut by the hard-ceiling truncation, so the incidental group scored 0.0% by luck, not by design, and the fixture passed on that. Bounding the oversize-member overshoot freed enough headroom that the response no longer truncates the same section away. Every file obeys the new bound on this repo (max ratio 1.40x of spendable, against the 1.5x ceiling). What the failure exposes is real and pre-existing: parse-run.mjs scores 18 against tools.ts's 58 yet is reserved a comparable slice — a low-scoring file taking a top-file share, which is epic CG-24's subject. Fix it there; do not tune the CG-30 bound to restore a pass that depended on truncation."
       }
     }
   ]