docs: file #260 - portal-network wedge reproduced live (stuck action gate + LOH leak)

First solid reproduction of the Coldeve findings: after sustained walked portal-network use the client wedges - server-round-trip actions (portal use, combat toggle) produce zero outbound send while client-predicted movement still works, and the LOH climbs to 574 MB. Combat toggle x3 with no send is the smoking gun for the one-request-at-a-time use gate latching closed on an unacked UseWithTarget. gcdump captured in the broken state. Supersedes the framing of #256/#257 - both are likely facets. Investigation not started; forbidden workaround (gate timeout) called out explicitly.

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

docs/ISSUES.md

@@ -97,6 +97,58 @@ Copy this block when adding a new issue:
 
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+## #260 — Portal-network wedge: server-round-trip actions die, LOH leaks — REPRODUCED
+
+**Status:** OPEN — reproduced live, forensics captured, investigation not started
+**Severity:** HIGH (renders the client unplayable after sustained portal use)
+**Filed:** 2026-07-29 (instrumented Coldeve session, Vulkan backend)
+**Component:** interaction/use transaction gate + inbound stream + managed memory
+**Supersedes framing of:** #256 (invisible portal-network objects) and #257
+(~1.5 GB working set) — both are almost certainly facets of this.
+
+**Reproduction (the first solid one):** on Coldeve (`play.coldeve.ac`), character
+Barris, after several portal-network runs returning to the town portal network,
+the client wedged: **portals unusable, combat mode won't toggle, portals/signs
+missing** — while **movement still works**.
+
+**Evidence captured (`artifacts/coldeve-repro-20260729/`, gitignored, local):**
+gcdump taken *in the broken state* (15 MB), full session log with
+`[cell-transit]`/`[input]`/`[use-target]`/`equipment` traces, the
+`dotnet-counters` CSV, and stderr.
+
+**Two symptoms, established from the traces:**
+1. **The outbound action pipeline is wedged.** `CombatToggleCombat Press` × 3
+   produced **zero outbound send** (movement, being client-predicted, still
+   produces `[cell-transit]`). Signature of the one-request-at-a-time
+   interaction/use gate (J5.2) latching closed because a `UseWithTarget` never
+   received its server ack — a burst of `[use-target] … SEND UseWithTarget`
+   precedes the hang. Every server-round-trip action (portal use, combat mode)
+   is then silently dropped; local-only actions still work.
+2. **A managed leak on the LOH — this one is ours.** `dotnet-counters` at wedge:
+   **LOH 601,807,472 B (574 MB)**, process WS 3.2 GB — distinct from the flat
+   ~1.9 GB residency *level* the V11 soak plateaued at (that was benign; this
+   climbs under live walked play). Fingerprint matches the project's prior LOH
+   leak class (per-event `float[]`/`byte[]` never released). 185 `equipment:
+   attached … RightHandCombat` re-attach lines but only 1 CreateObject, so it is
+   re-attach/replay churn on existing entities, not fresh-object accumulation.
+
+**Hypothesis (unproven, for the investigation):** a jammed inbound stream could
+both starve the ack the use-gate waits on AND accumulate LOH buffers — one root,
+two symptoms. Or two bugs. The gcdump names the LOH type by retainer; the log
+timeline names the unacked request. Not confirmed either way.
+
+**Why the scripted gates missed it:** the V11 portal-churn soak used `/teleloc`,
+which enters the transit state machine by a different door than a *walked* portal
+transit — exactly the gap the walked-play session was designed to probe.
+
+**Next (investigation, user-approved fix only):** read the gcdump retainer graph
+per `reference_memory_leak_toolchain.md`; reconstruct the use-gate timeline from
+the log to find the unacked request; determine shared-vs-separate root. Do NOT
+patch the symptom (a gate timeout would be the classic forbidden workaround) —
+find why the ack never lands.
+
+---
+
 ## #259 — Win32 Vulkan surface creation fails machine-wide (`ERROR_UNKNOWN`)
 
 **Status:** OPEN — environment fault, not a product defect; recorded so the next