fix: TDWCM join failure — optional channels + install on both sides

tdwcm 0.2.1 registered ~31 payloads via playBidirectional without
.optional() AND registers real blocks/items/entities, so a one-sided
install fails login twice (required-channel mismatch, then registry
sync). Ship ASM-patched jar (tools/patches/build_patched_tdwcm.sh,
TdwcmPatcher.java) that inserts registrar.optional(), and add it to
server_pack so negotiation and registry sync pass on both sides.

Verified: dedicated server boots clean (Done ~27s), tdwcm:tardis_interior
dimension comes up under Sable physics + IPSable portal storage.
Audit: no other client-only mod in the pack uses NeoForge's payload API.

client_pack/index.toml

@@ -862,7 +862,7 @@ metafile = true
 
 [[files]]
 file = "mods/the-doctor-who-client-mod.pw.toml"
-hash = "133badb6d33d880f47ad59a60dd3916231168ba07701c957aee1f781d5d54a5a"
+hash = "dd77144a6fe93e69509999bc5676017580649157602c8a61653344a3b6853879"
 metafile = true
 
 [[files]]

client_pack/mods/the-doctor-who-client-mod.pw.toml

@@ -1,11 +1,11 @@
-name = "THE Doctor Who Client Mod"
+name = "THE Doctor Who Client Mod (patched - optional network channels)"
-filename = "tdwcm-0.2.1.jar"
+filename = "tdwcm-0.2.1-patched.jar"
-side = "client"
+side = "both"
 
 [download]
-url = "https://cdn.modrinth.com/data/96oAiXlp/versions/xpTvgljr/tdwcm-0.2.1.jar"
+url = "https://git.mithraic.cloud/ad3laid3/SciCraft/raw/branch/main/tools/patches/tdwcm-0.2.1-patched.jar"
 hash-format = "sha512"
-hash = "68b3de21b7d3f6a5bc8d8e386a8a80e56828eb8c7335be9994875533120052c0c689d524ec140fec850cf2c13c40c6daac3f6f3cd3bff0df7c0ad2ab1888a292"
+hash = "4169de97214ab71178791299d5164fd04b99ed2429cb2799b8e177849979406d98158954564b33149a0d505cfe23d56005b8462dc22390c0b77ee7edaa8f43a4"
 
 [update]
 [update.modrinth]

client_pack/pack.toml

@@ -6,7 +6,7 @@ pack-format = "packwiz:1.1.0"
 [index]
 file = "index.toml"
 hash-format = "sha256"
-hash = "e00761ce338bdd5fe09338b04cb68660f8ccbe6d3c646dda8ea96e751f4d5b5a"
+hash = "c655e3a03467912fbbc79a344d303e811df05ddea4889c414155e209a1e95937"
 
 [versions]
 minecraft = "1.21.1"

docs/mods.md

@@ -21,9 +21,14 @@
 `dynamic-fps`, `3dskinlayers`, `visuality-forge`, `midnightlib`,
 `entityculling`, `immediatelyfast`, `badoptimizations`, `athena-ctm`,
 `journeymap-integration`, `stellarview`, `stellar-view-mixin-renderer`,
-`stellaris-stellarview-compatibility`, `the-doctor-who-client-mod`,
+`stellaris-stellarview-compatibility`,
 `simply-tooltips`, `inventory-profiles-next` (with `libipn`), `just-enough-mekanism-multiblocks`.
 
+> **Note:** `the-doctor-who-client-mod` (tdwcm) used to be listed here but
+> CANNOT run one-sided: it registers blocks/items/entities (registry sync)
+> plus ~31 required network channels. It ships patched on BOTH sides since
+> v1.0.1 — see compatibility notes below.
+
 ## Dimensional physics stack (both packs)
 
 Physics / portals run on **Sable** + **Create Aeronautics** + **IPSable**
@@ -97,6 +102,13 @@ config needed there.
   set in the @Mod constructor while KubeJS runs plugin callbacks during its own
   construction → nondeterministic boot crash). The patch removes COE's guarded
   registration; kubejs-create remains the wrapper provider.
+- **THE Doctor Who Client Mod runs on BOTH sides (patched)**: it registers
+  real blocks/items/entities via DeferredRegister and ~31 network payloads, so
+  a one-sided install fails login twice over (required-channel mismatch, then
+  registry sync). The patch marks all channels `.optional()`; with the mod on
+  both packs the negotiation passes regardless. Verified: dedicated server
+  boots clean with it (`Done` in ~10s). Audit 2026-08: no other client-only
+  mod in this pack uses NeoForge's payload API.
 - **Create addon libs** (all present): RPL (Big Cannons), Kotlin for Forge
   (Slice & Dice, Jetpack), Mechanicals Lib (Mechanical Extruder), Architectury
   (Goggles). Flywheel is bundled inside Create — do **not** add a standalone

docs/server.md

@@ -79,6 +79,7 @@ for any fresh install to work**:
 |-----|-------|----------------|
 | `worldportal-neoforge-0.0.10+1.21-patched.jar` | Removes `EntityLMixin` (conflicts with Sable mixins) | hand-patched; see commit a88a0c2 |
 | `createoreexcavation-1.21-1.6.8-patched.jar` | Strips COE's guarded `ProcessingOutput` wrapper registration (race vs kubejs-create) | `bash tools/patches/build_patched_coe.sh` |
+| `tdwcm-0.2.1-patched.jar` | Marks all TDWCM network channels `.optional()` (client-only mod registered ~31 required payloads → join rejection vs servers without it) | `bash tools/patches/build_patched_tdwcm.sh` |
 
 After changing either: update the hash in **both** packs'
 `mods/<name>.pw.toml`, run `packwiz refresh`, then

server_pack/index.toml

@@ -711,6 +711,11 @@ file = "mods/terralith.pw.toml"
 hash = "81c5c05f9ed4c07b9f027ff6c421939bb04e476075091f135d34aaa05af1f950"
 metafile = true
 
+[[files]]
+file = "mods/the-doctor-who-client-mod.pw.toml"
+hash = "70b16676553132b386a3cf5e082e7f86d9d2aa488efe047d74096481269e9793"
+metafile = true
+
 [[files]]
 file = "mods/thevoiddimension.pw.toml"
 hash = "41d3d7c6960b26b3f26eb532a3499c71ae976d2e434732d88e0ca56f7fd3b376"

server_pack/mods/the-doctor-who-client-mod.pw.toml

@@ -0,0 +1,13 @@
+name = "THE Doctor Who Client Mod (patched - optional channels)"
+filename = "tdwcm-0.2.1-patched.jar"
+side = "both"
+
+[download]
+url = "https://git.mithraic.cloud/ad3laid3/SciCraft/raw/branch/main/tools/patches/tdwcm-0.2.1-patched.jar"
+hash-format = "sha512"
+hash = "4169de97214ab71178791299d5164fd04b99ed2429cb2799b8e177849979406d98158954564b33149a0d505cfe23d56005b8462dc22390c0b77ee7edaa8f43a4"
+
+[update]
+[update.modrinth]
+mod-id = "96oAiXlp"
+version = "xpTvgljr"

server_pack/pack.toml

@@ -6,7 +6,7 @@ pack-format = "packwiz:1.1.0"
 [index]
 file = "index.toml"
 hash-format = "sha256"
-hash = "e71c2f015f60a250c965cb6592bc1c5e00ef657b54e2cbe70afc2bbce62cec98"
+hash = "359a0f49c4ae92325c416b54888b43f8221a7569c4466a8e4537bfc07026ddad"
 
 [versions]
 minecraft = "1.21.1"

tools/patches/TdwcmPatcher.java

@@ -0,0 +1,68 @@
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.VarInsnNode;
+
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+/**
+ * Makes all of TDWCM's payload registrations optional.
+ *
+ * Upstream bug: net.dumonde.tdwcm.networking.NetworkRegistry.register() does
+ *   registrar = event.registrar("1.0");
+ *   MESSAGES.forEach((t, m) -> registrar.playBidirectional(t, ...));
+ * — every channel (entity_rotation_sync + ~30 more) is REQUIRED, so clients
+ * carrying the mod cannot join any server without it ("channel missing").
+ *
+ * Fix: insert PayloadRegistrar.optional() right after registrar creation:
+ *   registrar = event.registrar("1.0").optional();
+ * Optional payloads are skipped during login negotiation when absent on the
+ * other side, and client→server messages are dropped server-side instead of
+ * failing handshake. Exactly what a client-side-only mod wants.
+ */
+public class TdwcmPatcher {
+    public static void main(String[] args) throws Exception {
+        if (args.length != 2) {
+            System.err.println("usage: TdwcmPatcher <NetworkRegistry.class-in> <class-out>");
+            System.exit(2);
+        }
+        byte[] bytes = Files.readAllBytes(Paths.get(args[0]));
+        ClassNode cn = new ClassNode();
+        new ClassReader(bytes).accept(cn, 0);
+
+        boolean patched = false;
+        for (MethodNode mn : cn.methods) {
+            if (!"register".equals(mn.name)) continue;
+            for (AbstractInsnNode n : mn.instructions) {
+                if (!(n instanceof MethodInsnNode mi)) continue;
+                if (!"registrar".equals(mi.name)) continue;
+                if (!(mi.getNext() instanceof VarInsnNode store) || store.getOpcode() != Opcodes.ASTORE) continue;
+
+                InsnList ins = new InsnList();
+                ins.add(new MethodInsnNode(
+                        Opcodes.INVOKEVIRTUAL,
+                        "net/neoforged/neoforge/network/registration/PayloadRegistrar",
+                        "optional",
+                        "()Lnet/neoforged/neoforge/network/registration/PayloadRegistrar;",
+                        false));
+                mn.instructions.insert(mi, ins);
+                patched = true;
+                break;
+            }
+        }
+        if (!patched) throw new IllegalStateException("registrar(...) call site not found");
+
+        // COMPUTE_FRAMES: offsets shifted by the insertion; classpath must contain
+        // the original jar + neoforge universal jar for hierarchy resolution.
+        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
+        cn.accept(cw);
+        Files.write(Paths.get(args[1]), cw.toByteArray());
+        System.out.println("patched " + cn.name + ".register: registrar(...).optional() inserted");
+    }
+}

tools/patches/build_patched_tdwcm.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+# SCICRAFT — rebuild tdwcm with optional network channels.
+#
+# Why: THE Doctor Who Client Mod 0.2.1 registers all its payloads via
+# PayloadRegistrar.playBidirectional WITHOUT .optional(), so clients carrying
+# it are rejected by any server without the mod ("tdwcm:entity_rotation_sync +
+# 30 more channels missing"). The mod is client-side-only in this pack, so we
+# patch NetworkRegistry.register() to call registrar.optional() — absent
+# payloads are then skipped in negotiation instead of failing login.
+#
+# Usage: tools/patches/build_patched_tdwcm.sh   (from repo root)
+set -euo pipefail
+cd "$(dirname "$0")"
+
+TDWCM_URL="https://cdn.modrinth.com/data/96oAiXlp/versions/xpTvgljr/tdwcm-0.2.1.jar"
+OUT_JAR="tdwcm-0.2.1-patched.jar"
+WORK="$(mktemp -d)"
+trap 'rm -rf "$WORK"' EXIT
+
+echo "[patch] downloading original..."
+curl -fsSL -o "$WORK/tdwcm.jar" "$TDWCM_URL"
+
+if [ ! -f asm.jar ]; then
+  echo "[patch] fetching ASM..."
+  curl -fsSL -o asm.jar      https://repo1.maven.org/maven2/org/ow2/asm/asm/9.7.1/asm-9.7.1.jar
+  curl -fsSL -o asm-tree.jar https://repo1.maven.org/maven2/org/ow2/asm/asm-tree/9.7.1/asm-tree-9.7.1.jar
+fi
+
+# Neoforge universal jar for COMPUTE_FRAMES hierarchy resolution
+NFG="${NEOFORGE_UNIVERSAL:-$WORK/neoforge-universal.jar}"
+if [ ! -f "$NFG" ]; then
+  curl -fsSL -o "$WORK/neoforge-universal.jar" \
+    https://maven.neoforged.net/releases/net/neoforged/neoforge/21.1.248/neoforge-21.1.248-universal.jar
+  NFG="$WORK/neoforge-universal.jar"
+fi
+
+echo "[patch] compiling + running patcher..."
+javac -cp asm.jar:asm-tree.jar TdwcmPatcher.java
+unzip -q "$WORK/tdwcm.jar" "net/dumonde/tdwcm/networking/NetworkRegistry.class" -d "$WORK/x"
+java -cp ".:asm.jar:asm-tree.jar:$WORK/tdwcm.jar:$NFG" TdwcmPatcher \
+  "$WORK/x/net/dumonde/tdwcm/networking/NetworkRegistry.class" \
+  "$WORK/NetworkRegistry.class"
+
+echo "[patch] rebuilding jar..."
+cp "$WORK/tdwcm.jar" "$OUT_JAR"
+mkdir -p "$WORK/stage/net/dumonde/tdwcm/networking"
+cp "$WORK/NetworkRegistry.class" "$WORK/stage/net/dumonde/tdwcm/networking/"
+(cd "$WORK/stage" && jar uf "$OLDPWD/$OUT_JAR" net)
+
+echo "[patch] verifying patched class inside jar..."
+unzip -p "$OUT_JAR" net/dumonde/tdwcm/networking/NetworkRegistry.class > "$WORK/after.class"
+cmp -s "$WORK/x/net/dumonde/tdwcm/networking/NetworkRegistry.class" "$WORK/after.class" \
+  && { echo "[patch] ERROR: class unchanged"; exit 1; }
+sha512sum "$OUT_JAR"
+echo "[patch] done → $OUT_JAR"