ci: build the real OBS adapter on all three platforms

Two things: unbreak the Windows compile, and give macOS/Windows a libobs.

MSVC fix. test_json.cpp failed to compile on the Windows runner with
"a universal-character-name specifies an invalid character" and "illegal
escape sequence" -- MSVC still forms escape sequences and
universal-character-names INSIDE raw string literals, which it must not.
Every JSON input containing a backslash is now built by string concatenation
from a single kBS constant, which also sidesteps the separate murky corner of
translation phase 1 where a doubled backslash immediately followed by 'u' has
historically been treated inconsistently. Same 158 checks, no behaviour
change.

OBS SDK bootstrap for macOS/Windows. Adopts obsproject/obs-plugintemplate's
buildspec machinery -- buildspec.json plus cmake/common/buildspec_common.cmake
and cmake/{macos,windows}/buildspec.cmake -- so those two platforms get a real
libobs and build the actual plugin module instead of only the core library.
Linux is untouched and still uses Ubuntu's libobs-dev
(-DSTPLUGIN_BOOTSTRAP_OBS=OFF); the bootstrap only runs where there is no
system package.

Trimmed against upstream, each change recorded in the file that makes it:

 - qt6 is dropped from dependencies_list on both platforms. The properties UI
   is plain obs_properties_* and nothing here links Qt.
 - The OBS sub-build builds and installs the `libobs` target, not
   `obs-frontend-api`. Building the frontend API is what would drag Qt back in,
   and this plugin never calls it.
 - The sub-build is configured with ENABLE_UI=OFF and ENABLE_SCRIPTING=OFF as
   well as upstream's ENABLE_FRONTEND=OFF: the pinned OBS predates
   ENABLE_FRONTEND and gates its Qt-dependent UI on ENABLE_UI, so without this
   it configures the whole OBS UI and demands Qt anyway.
 - Only the Release configuration is built and installed, not Debug as well.
   Nothing consumes a debug libobs and it doubles the slowest CI step.
 - Only the dependency-acquisition modules are vendored. The template's
   compilerconfig/defaults/helpers/xcode modules drive its own target and
   bundle layout, which this project does not use.

obs-studio is pinned to 30.0.2, deliberately low: OBS refuses to load a module
built against a NEWER libobs than the one running it and accepts older ones, so
this pin IS the minimum OBS version users need. 30.0.2 is also exactly what
Ubuntu 24.04's libobs-dev ships, which puts all three platforms on one floor,
and it supports the modern CMake layout the bootstrap drives via
-DOBS_CMAKE_VERSION=3.0.0. prebuilt is obs-deps 2023-11-03 with the hashes
obs-studio 30.0.2's own buildspec.json publishes; the obs-studio source
archive hashes were computed from the GitHub tag archives.

The workflow also prints what was actually produced on each platform (ldd /
otool / dir over build/package) and uploads it as an artifact, so "does this
even link against libobs" is answered by CI output rather than assumed.

Verified locally: the Linux path is unchanged by all of this -- a fresh
configure still finds libobs-dev, and ctest is 6/6. The macOS and Windows
bootstrap can only be verified by CI; that is what this push is for.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RL8abRmgFXkVASHkkqiJbE

.gitea/workflows/build.yml

@@ -1,8 +1,14 @@
 name: Build
 
-# Scaffolding CI: proves the CMake toolchain configures and builds on all
-# three platforms the design doc names. It does not yet link livekit-ffi
-# or produce a real OBS-installable package -- see README.md.
+# Every job builds the real plugin: the core library linked against the
+# pinned livekit/client-sdk-cpp release, and -- where libobs is available --
+# the OBS adapter module itself.
+#
+# Linux gets libobs from Ubuntu's libobs-dev. macOS and Windows have no
+# equivalent system package, so they run obs-plugintemplate's buildspec
+# bootstrap (buildspec.json + cmake/common/buildspec_common.cmake), which
+# downloads the pinned obs-deps bundle and obs-studio source and builds just
+# `libobs`. That step is the slow one: several minutes on a cold runner.
 
 on:
   push:
@@ -19,10 +25,12 @@ jobs:
       - name: Install build dependencies
         run: |
           sudo apt-get update -qq
-          sudo apt-get install -y -qq cmake ninja-build libobs-dev
+          sudo apt-get install -y -qq cmake ninja-build libobs-dev libcurl4-openssl-dev
 
       - name: Configure
-        run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
+        # Linux keeps its distribution libobs; the buildspec bootstrap is for
+        # the two platforms that have no such package.
+        run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTPLUGIN_BOOTSTRAP_OBS=OFF
 
       - name: Build
         run: cmake --build build
@@ -30,6 +38,19 @@ jobs:
       - name: Test (core library)
         run: ctest --test-dir build --output-on-failure
 
+      - name: Show what was built
+        run: |
+          ls -la build/package/bin build/package/data/locale build/package/licenses
+          ldd build/package/bin/streamer-tools-camera.so | grep -E 'obs|livekit'
+          nm -D build/package/bin/streamer-tools-camera.so | grep -E ' T obs_module_(load|unload)'
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-linux-x64
+          path: build/package
+
   macos:
     name: macOS (macos-latest)
     runs-on: macos-latest
@@ -41,10 +62,8 @@ jobs:
         run: brew install cmake ninja
 
       - name: Configure
-        # libobs is not expected to be found here yet (no Homebrew
-        # formula / SDK download wired up in this pass) -- the top-level
-        # CMakeLists.txt falls back to building only the core library in
-        # that case. See README.md.
+        # The buildspec bootstrap runs here: it fetches obs-deps + the pinned
+        # obs-studio source and builds libobs before this project configures.
         run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
 
       - name: Build
@@ -53,6 +72,18 @@ jobs:
       - name: Test (core library)
         run: ctest --test-dir build --output-on-failure
 
+      - name: Show what was built
+        run: |
+          ls -la build/package/bin || true
+          otool -L build/package/bin/streamer-tools-camera.so || true
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-macos
+          path: build/package
+
   windows:
     name: Windows (windows-latest)
     runs-on: windows-latest
@@ -61,22 +92,29 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install build dependencies
-        # winvm-builder is a self-hosted act_runner labeled
-        # "windows-latest" -- it is NOT the GitHub-hosted windows-latest
-        # image, so none of the tools that image preinstalls (cmake
-        # included) can be assumed present. Confirmed by a first CI run
-        # on this repo: "cmake : The term 'cmake' is not recognized...".
-        # lukka/get-cmake downloads a pinned cmake+ninja binary and adds
-        # it to PATH for this job, with no admin/choco dependency.
+        # winvm-builder is a self-hosted act_runner labeled "windows-latest";
+        # it is NOT the GitHub-hosted image, so none of that image's
+        # preinstalled tooling (cmake included) can be assumed present.
         uses: lukka/get-cmake@latest
 
       - name: Configure
-        # Same story as macOS: no OBS SDK available yet on this runner,
-        # so this proves the core library + MSVC toolchain only.
-        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+        # The default Visual Studio generator is required, not Ninja:
+        # cmake/windows/buildspec.cmake keys the dependency slice off
+        # CMAKE_VS_PLATFORM_NAME, which only a VS generator sets.
+        run: cmake -S . -B build -A x64
 
       - name: Build
         run: cmake --build build --config Release
 
       - name: Test (core library)
         run: ctest --test-dir build -C Release --output-on-failure
+
+      - name: Show what was built
+        run: dir build\package\bin
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-windows-x64
+          path: build/package