refactor(network): Remove legacy Send Delay

[githubawn]

What this code did:

The SendDelay setting (m_firewallSendDelay) enabled a specialized NAT traversal mode (FIREWALL_TYPE_NETGEAR_BUG) in FirewallHelper.cpp and NAT.cpp:

1. During pre-game connection setup, it inserted artificial delays (m_timeTillNextSend = -1) on outbound UDP STUN/probe packets sent to peer players.
2. In NAT::establishConnectionPaths(), it rearranged player connection slots into special pairs for nodes identified as having the Netgear NAT bug.
3. In NAT::probed() and NAT::gotMangledPort(), it blocked local clients from sending reciprocal NAT probes until the remote peer probed them first.
4. Exposed a "Send Delay" checkbox in the in-game Options Menu GUI and saved/loaded SendDelay = yes/no in Options.ini.

Background & Reason for Removal:

• Historical Workaround: Added in 2003 specifically for early consumer routers (e.g., Netgear WGR614 v1/v2, WGT624) that violated UDP Binding Stability and Endpoint-Independent Mapping per RFC 4787 (their stateful NAT tables prematurely flushed active socket bindings if rapid UDP packets were sent to multiple STUN mangler destinations).
• Hardware Extinction: Global IPv4 Shodan/Censys scans confirm these 20-year-old 802.11b/g routers are extinct.
• Community Confusion: Over the last 20 years, players frequently confused "Send Delay" in the Options GUI with in-game input lag or network ping delays, leading to endless forum troubleshooting guides instructing users to manually set SendDelay = no in Options.ini. In reality, it had zero effect on in-game performance.
• Code Cleanliness: Removing this eliminates non-standard probe delays in NAT.cpp, removes dead code across FirewallHelper, OptionPreferences, and GlobalData, and hides the obsolete setting from the Options GUI.

[greptile-apps]

Greptile Summary

This PR removes the legacy SendDelay / FIREWALL_TYPE_NETGEAR_BUG NAT-traversal workaround that was originally written in 2003 for early Netgear routers whose NAT tables would flush under rapid UDP traffic. The workaround is extinct-hardware-specific and had been causing user confusion for years because the Options-menu checkbox was mistaken for a general lag setting.

• Core removal (FirewallHelper, NAT, OptionPreferences, GlobalData): All detection, pairing, and probe-delay logic tied to FIREWALL_TYPE_NETGEAR_BUG and m_firewallSendDelay is deleted from both the Generals and Zero Hour code paths, with the #if defined(DEBUG_LOGGING) guard in NAT::doThisConnectionRound correctly extended to cover variables that are now log-only.
• GUI cleanup (OptionsMenu.cpp × 2): Save/load references for the Send Delay checkbox are removed unconditionally, and the checkbox widget is hidden inside an #if ENABLE_GUI_HACKS block — leaving the widget visible and interactable (but silently non-functional) in builds where that macro is not defined.

Confidence Score: 4/5

Safe to merge for builds where ENABLE_GUI_HACKS is always defined; needs attention if non-ENABLE_GUI_HACKS builds ship to players.

The network logic removal is thorough and the NAT connection flow remains correct for all non-Netgear cases. The only real concern is that the Options-menu Send Delay checkbox hiding is conditional on ENABLE_GUI_HACKS, while all its save/load wiring was removed unconditionally — so in any build where the macro is absent the widget is live but does nothing, which could confuse players and would contradict one of the PR stated goals.

Files Needing Attention: Generals/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp and its GeneralsMD counterpart — the conditional vs. unconditional removal asymmetry for the Send Delay checkbox.

Important Files Changed

Filename	Overview
Core/GameEngine/Include/GameNetwork/FirewallHelper.h	Removes the FIREWALL_TYPE_NETGEAR_BUG enum value and both isNetgear() overloads; straightforward dead-code removal.
Core/GameEngine/Source/GameNetwork/FirewallHelper.cpp	Removes all m_firewallSendDelay / FIREWALL_TYPE_NETGEAR_BUG references and dead #if (0) block; clean removal with no behavioral gaps.
Core/GameEngine/Source/GameNetwork/NAT.cpp	Removes Netgear pairing loop and probe-delay logic; the connectionAssigned[i] == TRUE guard at the top of the remaining assignment loop is now dead code (always false), but harmless.
Generals/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp	GUI hiding of Send Delay checkbox is guarded by #if ENABLE_GUI_HACKS, but all save/load logic was removed unconditionally — leaving the checkbox visible and enabled but non-functional in builds without that macro.
GeneralsMD/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp	Same ENABLE_GUI_HACKS asymmetry as the Generals variant — checkbox remains visible and enabled but non-functional in builds without the macro.

Sequence Diagram

sequenceDiagram
    participant UI as Options Menu
    participant GP as GlobalData
    participant FH as FirewallHelper
    participant NAT as NAT

    note over UI,NAT: Before (with SendDelay / Netgear path)
    UI->>GP: "m_firewallSendDelay = getSendDelay()"
    GP->>FH: detectionBeginUpdate sets FIREWALL_TYPE_NETGEAR_BUG
    FH->>NAT: establishConnectionPaths (Netgear pairing loop)
    NAT->>NAT: "doThisConnectionRound sets m_timeTillNextSend = -1"
    NAT->>NAT: gotMangledPort waits for m_beenProbed before probing

    note over UI,NAT: After (this PR)
    UI-->>GP: (no SendDelay read)
    GP->>FH: detectionBeginUpdate (no Netgear branch)
    FH->>NAT: establishConnectionPaths (simple slot to node assignment)
    NAT->>NAT: doThisConnectionRound probes immediately
    NAT->>NAT: gotMangledPort always calls sendAProbe()

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Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
Generals/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp:955-960
**Checkbox hidden only under `ENABLE_GUI_HACKS`, but save/load removed unconditionally**

The "Send Delay" checkbox is hidden inside `#if ENABLE_GUI_HACKS`, but every save (`saveOptions`) and load (`OptionsMenuInit` → `GadgetCheckBoxSetChecked`) reference was removed unconditionally. In any build where `ENABLE_GUI_HACKS` is not defined, the checkbox remains visible and enabled in the Options GUI — users can toggle it freely — but the state is never persisted and has no effect. The same asymmetry is present in `GeneralsMD/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp`.

_{Reviews (3): Last reviewed commit: "refactor(network): Put Send Delay check ..." | Re-trigger Greptile}

[bobtista]

Left one question, otherwise this looks good