.gitea/workflows/fbs-codegen.yaml

@@ -0,0 +1,80 @@
+name: Tests · FBS codegen
+
+# Guards that the committed FlatBuffers bindings (Go under
+# pkg/schema/fbs/<schema>/ and TS under ui/frontend/src/proto/galaxy/fbs/)
+# are exactly what the pinned flatc produces from the .fbs schemas.
+# Catches both "changed a schema but forgot to regenerate" and
+# "regenerated with the wrong flatc version" (e.g. a distro's older
+# flatbuffers-compiler), which silently churns output and can flip
+# nullable-scalar wire defaults. Path-filtered so it only runs when the
+# schemas, the generated trees, the fbs Makefiles, or this workflow change.
+
+on:
+  push:
+    paths:
+      - 'pkg/schema/fbs/**'
+      - 'ui/frontend/src/proto/galaxy/fbs/**'
+      - 'ui/Makefile'
+      - '.gitea/workflows/fbs-codegen.yaml'
+  pull_request:
+    paths:
+      - 'pkg/schema/fbs/**'
+      - 'ui/frontend/src/proto/galaxy/fbs/**'
+      - 'ui/Makefile'
+      - '.gitea/workflows/fbs-codegen.yaml'
+
+concurrency:
+  group: fbs-codegen-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  FLATC_VERSION: 25.9.23
+
+jobs:
+  codegen:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Cache flatc
+        id: cache-flatc
+        uses: actions/cache@v4
+        with:
+          path: ${{ runner.temp }}/flatc-bin
+          key: flatc-${{ env.FLATC_VERSION }}-linux-g++13
+
+      - name: Install pinned flatc
+        if: steps.cache-flatc.outputs.cache-hit != 'true'
+        run: |
+          mkdir -p "${{ runner.temp }}/flatc-bin"
+          curl -sSL -o /tmp/flatc.zip \
+            "https://github.com/google/flatbuffers/releases/download/v${FLATC_VERSION}/Linux.flatc.binary.g++-13.zip"
+          python3 -m zipfile -e /tmp/flatc.zip "${{ runner.temp }}/flatc-bin"
+          chmod +x "${{ runner.temp }}/flatc-bin/flatc"
+
+      - name: Add flatc to PATH
+        run: echo "${{ runner.temp }}/flatc-bin" >> "$GITHUB_PATH"
+
+      - name: Verify flatc version
+        run: flatc --version
+
+      - name: Regenerate Go + TS bindings
+        run: |
+          make -C pkg/schema/fbs fbs-go
+          make -C ui fbs-ts
+
+      - name: Assert no drift
+        run: |
+          if ! git diff --exit-code || [ -n "$(git status --porcelain)" ]; then
+            echo "::error::Committed FlatBuffers bindings differ from a flatc ${FLATC_VERSION} regeneration."
+            echo "Run 'make -C pkg/schema/fbs fbs-go' and 'make -C ui fbs-ts' with flatc ${FLATC_VERSION} and commit the result."
+            git status --porcelain
+            git --no-pager diff
+            exit 1
+          fi

gateway/go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/alicebob/miniredis/v2 v2.37.0
 	github.com/getkin/kin-openapi v0.135.0
 	github.com/gin-gonic/gin v1.12.0
-	github.com/google/flatbuffers v25.12.19+incompatible
+	github.com/google/flatbuffers v25.9.23+incompatible
 	github.com/google/uuid v1.6.0
 	github.com/prometheus/client_golang v1.23.2
 	github.com/redis/go-redis/v9 v9.18.0

gateway/go.sum

@@ -73,8 +73,8 @@ github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/cel-go v0.27.0 h1:e7ih85+4qVrBuqQWTW4FKSqZYokVuc3HnhH5keboFTo=
 github.com/google/cel-go v0.27.0/go.mod h1:tTJ11FWqnhw5KKpnWpvW9CJC3Y9GK4EIS0WXnBbebzw=
-github.com/google/flatbuffers v25.12.19+incompatible h1:haMV2JRRJCe1998HeW/p0X9UaMTK6SDo0ffLn2+DbLs=
-github.com/google/flatbuffers v25.12.19+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
+github.com/google/flatbuffers v25.9.23+incompatible h1:rGZKv+wOb6QPzIdkM2KxhBZCDrA0DeN6DNmRDrqIsQU=
+github.com/google/flatbuffers v25.9.23+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=

integration/go.mod

@@ -36,7 +36,7 @@ require (
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-ole/go-ole v1.2.6 // indirect
-	github.com/google/flatbuffers v25.12.19+incompatible // indirect
+	github.com/google/flatbuffers v25.9.23+incompatible // indirect
 	github.com/jackc/pgx/v5 v5.9.2 // indirect
 	github.com/klauspost/compress v1.18.5 // indirect
 	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect

integration/go.sum

@@ -47,8 +47,8 @@ github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
 github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
-github.com/google/flatbuffers v25.12.19+incompatible h1:haMV2JRRJCe1998HeW/p0X9UaMTK6SDo0ffLn2+DbLs=
-github.com/google/flatbuffers v25.12.19+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
+github.com/google/flatbuffers v25.9.23+incompatible h1:rGZKv+wOb6QPzIdkM2KxhBZCDrA0DeN6DNmRDrqIsQU=
+github.com/google/flatbuffers v25.9.23+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=

pkg/schema/fbs/Makefile

@@ -0,0 +1,26 @@
+.PHONY: help fbs-go flatc-check
+
+# Pinned flatc version. The committed Go bindings under <schema>/ and the
+# flatbuffers Go runtime (go.mod) are on this version; the TS side mirrors
+# it via `make -C ui fbs-ts`. Generating with a different flatc silently
+# churns output and can flip nullable-scalar wire defaults, so fbs-go
+# refuses to run on a mismatch. Distro packages (e.g. Debian's
+# flatbuffers-compiler) are too old — use the release binary at $(FLATC_URL).
+REQUIRED_FLATC := 25.9.23
+FLATC_URL      := https://github.com/google/flatbuffers/releases/tag/v$(REQUIRED_FLATC)
+# Every schema in this directory. Listed explicitly (not a wildcard) so a
+# stray .fbs cannot silently change the generated set.
+FBS_INPUTS     := common.fbs lobby.fbs user.fbs report.fbs order.fbs diplomail.fbs battle.fbs gateway.fbs notification.fbs
+
+help:
+	@echo "schema/fbs targets:"
+	@echo "  fbs-go   FlatBuffers Go generation from *.fbs into <schema>/ (requires flatc $(REQUIRED_FLATC))"
+
+flatc-check:
+	@command -v flatc >/dev/null || { echo "flatc not found; install flatc $(REQUIRED_FLATC) from $(FLATC_URL) (distro packages such as Debian's flatbuffers-compiler are too old)"; exit 1; }
+	@flatc --version | grep -q "$(REQUIRED_FLATC)" || { echo "flatc $(REQUIRED_FLATC) required; found '$$(flatc --version)'. Get the pinned binary from $(FLATC_URL)"; exit 1; }
+
+# --go-module-name rewrites cross-namespace imports to the fully-qualified
+# module path so the generated code links without local replace directives.
+fbs-go: flatc-check
+	flatc --go --go-module-name galaxy/schema/fbs $(FBS_INPUTS)

pkg/schema/fbs/README.md

@@ -1,9 +1,32 @@
 # Flatbuffers schemas
 
+## Pinned flatc version
+
+The committed bindings — Go under `<schema>/` and TS under
+`ui/frontend/src/proto/galaxy/fbs/` — and the flatbuffers runtimes
+(`github.com/google/flatbuffers` in the Go modules, `flatbuffers` in
+`ui/frontend/package.json`) are all on **flatc 25.9.23**. Regenerate
+only with that exact version: a different flatc silently churns output
+and can flip nullable-scalar wire defaults (`= null` builder slots
+switch between the presence-preserving `null` form and the value-omitting
+`0` form). The `fbs-go` / `fbs-ts` targets refuse to run on a mismatch,
+and the `fbs-codegen` CI workflow fails if the committed bindings differ
+from a pinned-flatc regeneration.
+
+Distro packages are too old (e.g. Debian trixie ships `flatbuffers-compiler`
+23.5.26). Install the pinned binary from the release page:
+<https://github.com/google/flatbuffers/releases/tag/v25.9.23>.
+
 ## Generating sources
 
-Given a `.fbs` file, source code can be generated using `flatc` from
-this directory:
+Regenerate both sides with the pinned `flatc` on `PATH`:
+
+```shell
+make -C pkg/schema/fbs fbs-go   # Go bindings into pkg/schema/fbs/<schema>/
+make -C ui fbs-ts               # TS bindings into ui/frontend/src/proto/galaxy/fbs/
+```
+
+`fbs-go` runs, for every schema in this directory:
 
 ```shell
 flatc --go --go-module-name galaxy/schema/fbs {file}.fbs

pkg/schema/go.mod

@@ -2,4 +2,4 @@ module galaxy/schema
 
 go 1.26.0
 
-require github.com/google/flatbuffers v25.12.19+incompatible
+require github.com/google/flatbuffers v25.9.23+incompatible

pkg/schema/go.sum

@@ -1,2 +1,4 @@
+github.com/google/flatbuffers v25.9.23+incompatible h1:rGZKv+wOb6QPzIdkM2KxhBZCDrA0DeN6DNmRDrqIsQU=
+github.com/google/flatbuffers v25.9.23+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/flatbuffers v25.12.19+incompatible h1:haMV2JRRJCe1998HeW/p0X9UaMTK6SDo0ffLn2+DbLs=
 github.com/google/flatbuffers v25.12.19+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=

pkg/transcoder/go.mod

@@ -3,6 +3,6 @@ module galaxy/transcoder
 go 1.26.0
 
 require (
-	github.com/google/flatbuffers v25.12.19+incompatible
+	github.com/google/flatbuffers v25.9.23+incompatible
 	github.com/google/uuid v1.6.0
 )

pkg/transcoder/go.sum

@@ -1,2 +1,4 @@
-github.com/google/flatbuffers v25.12.19+incompatible h1:haMV2JRRJCe1998HeW/p0X9UaMTK6SDo0ffLn2+DbLs=
+github.com/google/flatbuffers v25.9.23+incompatible h1:rGZKv+wOb6QPzIdkM2KxhBZCDrA0DeN6DNmRDrqIsQU=
+github.com/google/flatbuffers v25.9.23+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

ui/Makefile

@@ -1,4 +1,4 @@
-.PHONY: help web wasm ts-protos fbs-ts gomobile desktop-mac desktop-win desktop-linux ios android all
+.PHONY: help web wasm ts-protos fbs-ts flatc-check gomobile desktop-mac desktop-win desktop-linux ios android all
 
 .DEFAULT_GOAL := help
 
@@ -7,12 +7,20 @@ WASM_EXEC   := frontend/static/wasm_exec.js
 TINYGO_ROOT := $(shell tinygo env TINYGOROOT 2>/dev/null)
 FBS_OUT     := frontend/src/proto/galaxy/fbs
 FBS_INPUTS  := ../pkg/schema/fbs/common.fbs ../pkg/schema/fbs/lobby.fbs ../pkg/schema/fbs/user.fbs ../pkg/schema/fbs/report.fbs ../pkg/schema/fbs/order.fbs ../pkg/schema/fbs/diplomail.fbs ../pkg/schema/fbs/battle.fbs
+# Pinned flatc version. The committed bindings (Go + TS) and the
+# flatbuffers Go/TS runtimes are all on this version; generating with a
+# different flatc silently churns output and can flip nullable-scalar
+# wire defaults, so fbs-ts refuses to run on a mismatch. Distro packages
+# (e.g. Debian's flatbuffers-compiler) are too old — use the release
+# binary at $(FLATC_URL).
+REQUIRED_FLATC := 25.9.23
+FLATC_URL      := https://github.com/google/flatbuffers/releases/tag/v$(REQUIRED_FLATC)
 
 help:
 	@echo "ui targets:"
 	@echo "  wasm           TinyGo build of ui/core to core.wasm + wasm_exec.js shim (Phase 5)"
 	@echo "  ts-protos      Connect-ES + Protobuf-ES generation from gateway/proto (Phase 5)"
-	@echo "  fbs-ts         FlatBuffers TS generation from pkg/schema/fbs/*.fbs (Phase 8)"
+	@echo "  fbs-ts         FlatBuffers TS generation from pkg/schema/fbs/*.fbs (requires flatc $(REQUIRED_FLATC))"
 	@echo "  web            Vite production build (Phase 5+)"
 	@echo "  gomobile       gomobile bind for iOS .framework + Android .aar (Phase 32+)"
 	@echo "  desktop-mac    Wails build for darwin/{arm64,amd64} (Phase 31)"
@@ -33,8 +41,11 @@ ts-protos:
 	@test -x frontend/node_modules/.bin/protoc-gen-es || { echo "protoc-gen-es not installed; run 'pnpm install' inside ui/frontend"; exit 1; }
 	buf generate ../gateway --template buf.gen.yaml --include-imports
 
-fbs-ts:
-	@command -v flatc >/dev/null || { echo "flatc not found; install via 'brew install flatbuffers' (macOS) or 'apt-get install -y flatbuffers-compiler' (Linux)"; exit 1; }
+flatc-check:
+	@command -v flatc >/dev/null || { echo "flatc not found; install flatc $(REQUIRED_FLATC) from $(FLATC_URL) (distro packages such as Debian's flatbuffers-compiler are too old)"; exit 1; }
+	@flatc --version | grep -q "$(REQUIRED_FLATC)" || { echo "flatc $(REQUIRED_FLATC) required; found '$$(flatc --version)'. Get the pinned binary from $(FLATC_URL)"; exit 1; }
+
+fbs-ts: flatc-check
 	mkdir -p $(FBS_OUT)
 	flatc --ts --gen-object-api -o $(FBS_OUT) $(FBS_INPUTS)
 

ui/frontend/src/proto/galaxy/fbs/order/command-item.ts

@@ -91,11 +91,11 @@ static addCmdId(builder:flatbuffers.Builder, cmdIdOffset:flatbuffers.Offset) {
 }
 
 static addCmdApplied(builder:flatbuffers.Builder, cmdApplied:boolean) {
-  builder.addFieldInt8(1, +cmdApplied, 0);
+  builder.addFieldInt8(1, +cmdApplied, null);
 }
 
 static addCmdErrorCode(builder:flatbuffers.Builder, cmdErrorCode:bigint) {
-  builder.addFieldInt64(2, cmdErrorCode, BigInt(0));
+  builder.addFieldInt64(2, cmdErrorCode, null);
 }
 
 static addPayloadType(builder:flatbuffers.Builder, payloadType:CommandPayload) {