docs+cleanup: env-var regression + Run↔Walk cycle bug filed; re-throttle diags

End-of-session cleanup of the 2026-05-03 remote-motion debug session.

Documentation:

- CLAUDE.md: add ⚠️ DO-NOT-ENABLE warning for ACDREAM_INTERP_MANAGER=1
  in the diagnostic env-vars list. Add an "Outbound motion wire format"
  section documenting acdream's WalkForward+HoldKey.Run encoding (which
  ACE auto-upgrades to RunForward on relay) so future sessions don't
  re-derive it.

- docs/ISSUES.md: file two new issues:
  * #39 — Run↔Walk cycle transition not visible on observed
    retail-driven player remotes when watched from acdream. Root cause
    located: ApplyServerControlledVelocityCycle is gated by
    IsPlayerGuid, excluding the exact case where ACE doesn't broadcast
    a UM (shift toggle while direction key held). Fix sketch ~10
    lines, separate commit. Cross-references the four-agent
    investigation prompt.
  * #40 — ACDREAM_INTERP_MANAGER=1 env-var path regressed. Documents
    why (e94e791 conflated MoveOrTeleport with update_object), the
    visible symptoms (staircase Z, position blips), and why
    Commit B (039149a)'s ResolveWithTransition port was insufficient
    (env-var path also clears body.Velocity → no horizontal Euler
    motion → sweep input is queue catch-up only, which stair-steps).
    Fix path = separate L.3 follow-up to re-integrate PositionManager
    additively on top of the legacy chain.

Code:

- GameWindow.cs:6042: prepend a ⚠️ REGRESSED warning block at the top
  of the env-var per-frame branch so anyone reading the code is
  immediately aware not to enable it. Cross-references ISSUES.md #40.

- AnimationSequencer.cs: re-throttle [SCFAST]/[SCFULL] diagnostics to
  0.5s per instance (rolled back from A.1's unthrottled experiment).
  Already served its purpose; throttled is enough for steady-state
  diagnostics. Restore _lastSetCycleDiagTime field.

No behavior change for any current launch (env-var unset = legacy
path unchanged). Build green; baseline test failures (8) unchanged
from prior commit, none introduced by this session.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CLAUDE.md

@@ -548,6 +548,41 @@ via `PlayerMovementController.ApplyServerRunRate`) or from
   (default 2 = 5×5).
 - `ACDREAM_NO_AUDIO=1` — suppress OpenAL init for headless / driver-
   broken setups.
+- `ACDREAM_REMOTE_VEL_DIAG=1` — dump per-tick / per-UM remote motion
+  diagnostics (`[UM_RAW]`, `[SCFAST]`, `[SCFULL]`, `[SETCYCLE]`,
+  `[FWD_WIRE]`, `[OMEGA_DIAG]`, `[SEQSTATE]`, `[PARTSDIAG]`,
+  `[VEL_DIAG]`, `[UPCYCLE]`). Heavy.
+- ⚠️ `ACDREAM_INTERP_MANAGER=1` — **DO NOT ENABLE.** This was an
+  experimental rewrite (e94e791) of the per-tick remote motion path.
+  It's regressed: the env-var path drops the per-tick collision sweep
+  (`ResolveWithTransition`) that the default path retains, causing a
+  visible "staircase" pattern when remotes run up/down slopes (body
+  Z stays flat between UPs, snaps at each one) plus position blips
+  during steady-state motion. Default (env-var unset) uses the
+  working retail-port chain. The PositionManager class itself is
+  fine and retail-faithful; only the integration into per-tick was
+  wrong. To be re-done in a future L.3 follow-up phase as additive
+  refinement on top of the working chain.
+
+### Outbound motion wire format (acdream → ACE)
+
+Important quirk for cross-checking observed remote behavior. acdream's
+`PlayerMovementController` + `MoveToState` builder encode motion as:
+
+| Local input | Wire `ForwardCommand` | Wire `HoldKey` | Wire `ForwardSpeed` |
+|---|---|---|---|
+| W (run) | `WalkForward` (0x05) | `Run` (2) | server runRate (~2.4–2.94) |
+| W + Shift (walk) | `WalkForward` (0x05) | `None` (1) | 1.0 |
+
+ACE auto-upgrades `WalkForward + HoldKey.Run` → `RunForward (0x07)`
+when relaying to remote observers. So our INBOUND parser sees
+`fwd=0x07` for "remote is running." This matches retail's encoding.
+
+When the local player toggles Shift while keeping W held (Run↔Walk
+demote/promote), acdream sends a fresh `MoveToState` with the new
+HoldKey + ForwardSpeed. Retail's outbound likely does the same, but
+ACE's behavior on relay is uncertain — see `#L.X` in ISSUES.md for
+the open Run↔Walk cycle bug on observed retail-driven remotes.
 
 ### Visual verification workflow