feat(retail): Commit B — retail-faithful AP cadence + screen-rect picker

Retires divergences flagged in the 2026-05-16 faithfulness audit:

1. AP cadence. Replaces the 1 Hz idle / 10 Hz active flat heartbeat
   with a diff-driven model gated on `Contact && OnWalkable`
   (acclient_2013_pseudo_c.txt:700327 SendPositionEvent). Sends on
   position or cell change while grounded on walkable, plus a 1 sec
   heartbeat; suppressed entirely airborne. PlayerMovementController
   exposes `NotePositionSent(pos, cellId, now)` which GameWindow stamps
   after each AutonomousPosition / MoveToState send — mirrors retail's
   shared `last_sent_position_time` between SendPositionEvent
   (0x006b4770) and SendMovementEvent (0x006b4680). Known divergence
   from retail: ours is per-frame-while-moving, retail's effective rate
   is ~1 Hz during smooth motion (cell/plane checks). Filed as #74,
   blocked by #63 — when #63 lands we revert to retail's narrower gate.

2. Workaround retirement. Removes TinyMargin (0.05 m inside arrival)
   and the AP-flush before re-send (`SendAutonomousPositionNow`). The
   diff-driven cadence makes both obsolete. Close-range turn-first
   deferred Use is kept (it IS retail — ACE Player_Move.cs:66-87
   mirrors retail's CreateMoveToChain pre-callback rotation), renamed
   `OnAutoWalkArrivedSendDeferredAction` to clarify it's a FIRST send.
   `isRetryAfterArrival` parameter dropped.

3. Far-range Use/PickUp retry. Restored — was load-bearing, not the
   "redundant cleanup" the Group 2 audit thought. Issue #63 means ACE
   drops the first Use as too-far without re-polling on subsequent APs;
   the arrival re-send is what makes far-range Use complete. Logs
   include `(queued for arrival re-send pending #63)` to make this
   explicit. Removes when #63 closes.

4. Screen-rect picker. New `AcDream.Core.Selection.ScreenProjection`
   helper shared by `WorldPicker` and `TargetIndicatorPanel`. The
   `Setup.SelectionSphere` projects to a screen-space square (retail
   anchor `SmartBox::GetObjectBoundingBox` 0x00452e20); picker
   hit-tests the mouse pixel against the same rect the indicator draws,
   inflated by 8 px (`TriangleSize`). Guarantees what-you-see is
   what-you-click — including rect corners that were dead zones under
   the old ray-sphere picker. Per-type radius (1.0/1.6/2.0 m) and
   vertical-offset (0.2/0.9/1.0/1.5 m) heuristic lambdas retired;
   `IsTallSceneryGuid` deleted; `EntityHeightFor` trimmed to 1.5 m × scale
   defensive default. No defensive sphere synth — entities without a
   baked `SelectionSphere` are skipped, matching retail's
   `GfxObjUnderSelectionRay` (0x0054c740).

5. Rotation rate run multiplier (Commit A precursor). `TurnRateFor(running)`
   helper applies retail's `run_turn_factor = 1.5f` (PDB-named
   0x007c8914) under HoldKey.Run, matching `apply_run_to_command` at
   0x00527be0 (line 305098). Effective: walking ≈ 90°/s, running ≈ 135°/s.
   Keyboard A/D + ApplyAutoWalkOverlay both use it.

6. Useability gate (Commit A precursor). `IsUseableTarget` corrected to
   `useability != 0` per `ItemUses::IsUseable` at 256455 — ANY non-zero
   passes (USEABLE_NO=1, USEABLE_CONTAINED=8, etc.), not just the
   USEABLE_REMOTE bit. Cross-checked against 4 call sites in retail
   (ItemHolder::UseObject 0x00588a80, DetermineUseResult 0x402697,
   UsingItem 0x367638, disable-button-state 0x198826). Added
   `ProbeUseabilityFallbackEnabled` diagnostic
   (`ACDREAM_PROBE_USEABILITY_FALLBACK=1`) to measure how often the
   creature/BF_DOOR fallback fires for ACE-seed-DB entities with
   null useability.

CLAUDE.md updated with the graceful-shutdown rule for relaunch:
Stop-Process bypasses the logout packet, leaving ACE's session marked
logged-in for ~3+ min. CloseMainWindow() sends WM_CLOSE so the
shutdown hook runs and the logout packet reaches ACE.

Tests: +3 ScreenProjectionTests + 6 WorldPickerRectOverloadTests = +9.
Core.Net 294/294 pass; Core 1073/1081 (8 pre-existing Physics failures
unchanged). Visual-verified 2026-05-16: rotation rate, useability,
screen-rect click area, double-click + R-key + F-key Use/PickUp at
short and long range — dialogue/door/pickup fire on arrival.

Filed follow-ups #70 (triangle apex/size DAT sprite), #71 (picker
Stage B polygon refine), #72 (cdb omega.z probe), #73 (retail-message
sweep pattern), #74 (per-frame AP chattier than retail — blocked by
#63). Old ray-sphere `WorldPicker.Pick(origin, direction, ...)`
overload kept for back-compat; no callers in acdream proper.

Plan: docs/superpowers/plans/2026-05-16-retail-faithfulness-fixes.md

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

CLAUDE.md

@@ -926,20 +926,50 @@ for the window to close.
 
 ### Logout-before-reconnect
 
-**ACE keeps your last session alive briefly after a disconnect.** If you
-relaunch the client within a few seconds of the last close, the handshake
-fails with `live: session failed: CharacterList not received` and the
-process exits with code 29. Wait ~3–5 seconds between launches, or explicitly
-kill stale processes:
+**ACE keeps your last session alive after a disconnect, and the duration
+depends on HOW the client exited.** Two cases:
+
+1. **Graceful close (client sent logout packet to ACE):** session clears
+   in ~3–5 seconds. Wait briefly between launches.
+2. **Hard kill (Stop-Process, crash, force-close):** no logout packet
+   reached ACE. ACE keeps the session marked logged-in until its own
+   timeout — observed in practice at ~3+ minutes. Subsequent relaunches
+   fail with `live: session failed: CharacterList not received` (exit 29)
+   the entire time. **There is no admin command available to us to kick
+   the stale session.** Either wait it out, or use the graceful path
+   below.
+
+**Prefer the graceful close path when ending a launch.** PowerShell's
+`Stop-Process` is a hard kill — it bypasses the client's shutdown hook
+which is where the logout packet would have been sent. The graceful
+alternative sends WM_CLOSE so the window's close handler runs:
 
 ```powershell
-Get-Process -Name AcDream.App -ErrorAction SilentlyContinue | Stop-Process -Force
+$proc = Get-Process -Name AcDream.App -ErrorAction SilentlyContinue
+if ($proc) {
+    $proc.CloseMainWindow() | Out-Null
+    if (-not $proc.WaitForExit(5000)) {
+        # Fell through to hard-kill — session WILL be stuck on ACE.
+        $proc | Stop-Process -Force
+    }
+}
 Start-Sleep -Seconds 3
 # ... then launch ...
 ```
 
-The user has repeatedly confirmed this — don't treat exit-29-after-rapid-relaunch
-as a code bug. It's a server-side session-cleanup delay.
+If `WaitForExit(5000)` returns false (the client didn't exit in 5 seconds
+after WM_CLOSE), the client is unresponsive and a hard kill is the only
+option — accept that ACE will be unhappy for a few minutes.
+
+**When recovering from a hard-killed session that ACE still considers
+active:** the only honest answer is to wait. Don't bother retrying every
+30 seconds — make a single retry attempt ~3 minutes after the kill, and
+if it still fails wait another 2 minutes before trying again. The user
+will likely volunteer when ACE has cleared the session if you ask.
+
+The user has repeatedly confirmed this — don't treat exit-29-after-relaunch
+as a code bug. It's a server-side session-cleanup delay whose duration is
+governed by whether the previous shutdown was graceful or forced.
 
 ### Test character