ci: add tag-triggered release packaging workflow

Adds .gitea/workflows/release.yml, triggered only on a pushed v* tag, which
builds all three platforms (reusing the exact same configure/build/test
commands as build.yml, now factored out into .gitea/scripts/ so the two
workflows can't drift), zips each platform's build/package/ output, and
creates a draft Gitea Release with the archives attached.

This is packaging automation only -- it does not resolve or bypass the C1
WebRTC/OpenH264 release gate documented in README.md's Status section.
Nothing publishes until a human deliberately pushes a version tag (which
should not happen before owner sign-off) and then explicitly publishes the
resulting draft. The generated release notes lead with a restatement of the
open C1 question specifically so that second step can't be taken by
accident.

build.yml is refactored (not rewritten) to call the same shared scripts;
its job/step behavior is otherwise unchanged.

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

.gitea/scripts/macos-build.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# Shared with .gitea/workflows/build.yml and .gitea/workflows/release.yml --
+# this is the actual macOS configure/build/test/verify sequence. Edit once,
+# here, so both workflows stay in sync instead of drifting copies.
+#
+# The buildspec bootstrap runs here: it fetches obs-deps + the pinned
+# obs-studio source and builds libobs before this project configures.
+#
+# If that fails, fall back to a core-library-only build rather than going
+# red: the core library and its tests are what this job mainly guards, and
+# the fallback is loud (a workflow warning, plus the check below reporting no
+# module) rather than silent. Do not remove the warning -- a green job that
+# quietly stopped building the plugin is worse than a red one.
+set -euo pipefail
+
+if ! cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release; then
+  echo "::warning::OBS SDK bootstrap failed on macOS; building the core library only. The plugin module was NOT built."
+  rm -rf build
+  cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTPLUGIN_BOOTSTRAP_OBS=OFF
+fi
+
+cmake --build build
+ctest --test-dir build --output-on-failure
+
+# Show what was built.
+#
+# This is not purely informational: the macOS bootstrap has been reliably
+# building the real module in CI (6/6 tests, artifact uploaded -- see
+# README), so a missing module here is a regression to fail loudly on, not
+# the old silent fallback. (This is separate from the macOS packaging gap in
+# README -- that the module doesn't yet load as an OBS.app bundle -- which
+# this check does not and cannot test.)
+ls -la .deps/Frameworks/libobs.framework/Resources/cmake || true
+if [ ! -f build/package/bin/streamer-tools-camera.so ]; then
+  echo "::error::no plugin module was built -- build/package/bin/streamer-tools-camera.so is missing. The macOS from-source libobs bootstrap is expected to succeed; treat this as a build failure, not a core-library-only fallback."
+  exit 1
+fi
+ls -la build/package/bin
+otool -L build/package/bin/streamer-tools-camera.so
+otool -L build/package/bin/streamer-tools-camera.so | grep -E 'obs|livekit'