feat(ci): Gitea Actions — dockerized web/docs/rust-ci images, Apple client CI, Mac runner

Three workflows: ci.yml (Rust workspace inside the punktfunk-rust-ci
builder image + web/docs-site build+typecheck), docker.yml (build+push
punktfunk-web, punktfunk-docs, punktfunk-rust-ci to git.unom.io — host
and native clients stay un-dockerized by design), apple.yml (host-mode
macos-arm64 runner: Rust core -> PunktfunkCore.xcframework ->
swift build + swift test).

ci/rust-ci.Dockerfile: Ubuntu 26.04 with the workspace's link deps
(FFmpeg 8, PipeWire, Opus, GL/EGL/GBM, xkbcommon, libcuda via the
580-server userspace as a link stub) + pinned rustup + node for the JS
actions. Verified end to end in-container: build, 141/141 tests, C ABI
harness; all three images seeded to the registry manually.

scripts/ci/setup-macos-runner.sh provisions the Mac (rustup + darwin
targets, Node tarball, gitea-runner 1.0.8 host mode, LaunchAgent with
DEVELOPER_DIR auto-detect for sudo-free Xcode selection). Docs in
docs-site/content/docs/ci.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs-site/content/docs/meta.json

@@ -7,12 +7,14 @@
     "implementation-plan",
     "roadmap",
     "m2-plan",
+    "apple-stage2-presenter",
     "---Setup---",
     "linux-setup",
     "headless-box",
     "gnome-box",
     "bazzite",
     "windows-host",
-    "dualsense-haptics"
+    "dualsense-haptics",
+    "ci"
   ]
 }