docs(issues): file #76 — Step 2 LiveSessionController attempt regressed

A first attempt at extracting LiveSessionController out of GameWindow.cs
(Step 2 of docs/architecture/code-structure.md §4) was implemented and
reverted in the same session after visual verification at Holtburg
exposed three regressions: chat input field accepted text but nothing
was sent; door/NPC double-click fired the Use packet outbound but had
no visible client-side effect; R + click-target auto-walk no longer
fired the deferred Use on arrival (re-opens issue #63 / #75 territory).

Filing as a tracked open issue so the next refactor attempt has a
clear root-cause-investigation starting point with four hypotheses to
test. Step 1 (eda936d) and the Rule 5 follow-up (32423c2) remain
clean and verified.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/ISSUES.md

@@ -46,6 +46,86 @@ Copy this block when adding a new issue:
 
 # Active issues
 
+## #76 — LiveSessionController extraction (Step 2) regresses interaction + chat outbound
+
+**Status:** OPEN
+**Severity:** MEDIUM (refactor blocker; doesn't affect main branch which is unchanged)
+**Filed:** 2026-05-16
+**Component:** app / refactor (Step 2 of `docs/architecture/code-structure.md` §4)
+
+**Description:** A first attempt at Step 2 — extracting `LiveSessionController`
+out of `GameWindow.cs` — was implemented and reverted in the same session
+on the `claude/hungry-tharp-b4a27b` worktree. Visual verification at
+Holtburg revealed:
+
+- Chat input field accepts text + Enter but nothing is sent (no echo, no
+  ACE response).
+- Double-click on doors / NPCs fires `[B.4b] use guid=... seq=N` outbound
+  (verified in `launch.log`) but no visible client-side effect (door doesn't
+  swing, NPC doesn't dialogue).
+- R + click-target produces `[B.4b] use-deferred guid=... seq=N`, the
+  player auto-walks to the target, but the deferred Use does NOT fire on
+  arrival (regresses the Phase B.6 / issue #63 / #75 work).
+
+The Step 1 (`eda936d` RuntimeOptions) and Rule 5 follow-up
+(`32423c2` DumpSteepRoof → PhysicsDiagnostics) commits are NOT affected
+and stay clean.
+
+**Root cause / status:** Unknown. The refactor preserved every event
+subscription line-for-line (verified by `git diff` — only one `_liveSession.X +=`
+line moved, all others present). The new shape:
+
+```
+TryStartLiveSession()
+  → _liveSessionController.CreateAndWire(_options, WireLiveSessionEvents)
+       → new WorldSession(endpoint)
+       → wireEvents(session)   // i.e. WireLiveSessionEvents(session)
+  → Chat.OnSystemMessage("connecting...")
+  → _liveSession.Connect(user, pass)
+  → ...character validation + EnterWorld + post-setup...
+```
+
+Looks identical to the original control flow. Hypotheses to test on a
+clean re-attempt:
+
+1. **Timing of `_liveSession` field assignment.** The new code assigns
+   `_liveSession` inside `WireLiveSessionEvents` before subscriptions
+   run, and again after CreateAndWire returns. The original code set
+   `_liveSession` once at the inline `new WorldSession(...)` site. A
+   subtle ordering bug between subscriptions and `_liveSession`'s
+   externally visible state may matter.
+2. **LiveCommandBus closure capture.** The `var liveSession = _liveSession;`
+   capture inside the chat handler block may have been getting a
+   different value than before — though the field IS set by the time
+   the capture happens (line 1 of `WireLiveSessionEvents`).
+3. **Inbound packet ordering.** ACE may be sending the first
+   StateUpdate / spawn stream BEFORE the EnterWorld dance completes in
+   the new flow; if subscriptions are wired but `_liveSession` field
+   is briefly inconsistent, an early handler call could see a partial
+   state. The `_liveSession?.Tick()` route now goes through
+   `_liveSessionController?.Tick()`; verify that's not the difference.
+4. **Some non-subscription side effect** in `WireLiveSessionEvents`
+   that wasn't carried over correctly — over-indentation suggests a
+   diff-friendly intermediate state; full re-indentation may surface
+   the bug.
+
+**Files (in the reverted state — recover from worktree git reflog or
+re-write):**
+- `src/AcDream.App/Net/LiveSessionController.cs` (new, ~115 LOC)
+- `src/AcDream.App/Rendering/GameWindow.cs` — `TryStartLiveSession` split
+  + new `WireLiveSessionEvents` method
+
+**Research:** No memory entry yet. If the re-attempt succeeds, add a
+`feedback_step2_extraction_pitfalls.md` capturing whichever hypothesis
+turned out to be the bug.
+
+**Acceptance:** Step 2 lands when the full M1 demo loop (walk Holtburg,
+double-click inn door + door swings, double-click NPC + NPC dialogues,
+F-key pickup on a ground item) works identically to the pre-refactor
+behavior, AND chat input echoes back through the panel.
+
+---
+
 ## #75 — [DONE 2026-05-16 · `f035ea3`] Auto-walk should drive body directly, not synthesize player-input
 
 **Status:** DONE