fix: complete the docs/→design/ and openapi→api/ rename references

The file moves (docs/ → design/, docs/api/openapi.json → api/openapi.json) landed
in d01a8fd, but the matching reference updates did not — so mgmt.rs's drift-test
`include_str!("../../../docs/api/openapi.json")` pointed at a path that no longer
exists and the host failed to build. This restores it and updates every reference:

  - mgmt.rs include_str! → ../../../api/openapi.json (fixes the build)
  - web/orval.config.ts codegen target, web/Dockerfile, .dockerignore
  - deb/rpm/Arch packaging install paths
  - CLAUDE.md, the .gitea CI workflows, code doc-comments, design-doc cross-links

docs-site route URLs (/docs/...) untouched.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/bootstrap-ubuntu.sh

@@ -205,5 +205,5 @@ cat <<'NEXT'
        export XDG_RUNTIME_DIR=/run/user/$(id -u) WAYLAND_DISPLAY=wayland-1
        swaymsg -t get_outputs                         # confirm HEADLESS-1
        bash scripts/headless/capture-smoke-test.sh    # wf-recorder -> hevc_nvenc -> /tmp/*.mkv
-  5. Then start M0 proper: see docs/linux-setup.md.
+  5. Then start M0 proper: see design/linux-setup.md.
 NEXT

scripts/ci/provision-windows-wdk.ps1

@@ -1,6 +1,6 @@
 # Provision the Windows Driver Kit (WDK) + cargo-wdk on the self-hosted windows-amd64 runner, so the
 # all-Rust UMDF drivers (pf-vdisplay + the gamepad drivers, unified on microsoft/windows-drivers-rs)
-# can build there. See docs/windows-host-rewrite.md (M0).
+# can build there. See design/windows-host-rewrite.md (M0).
 #
 # The runner already has the base Windows SDK 10.0.26100 (um/ headers) + MSVC + LLVM + Rust, but NOT the
 # WDK — no km/ + wdf/ + um/iddcx headers, no inf2cat/stampinf/devgen. wdk-sys's bindgen needs those.

scripts/headless/run-headless-sway.sh

@@ -5,7 +5,7 @@
 # ScreenCast portal (xdg-desktop-portal-wlr) and the punktfunk host share one bus. After this
 # is up, run `prepare-session.sh` from a second shell to set the mode + portal env.
 #
-# Prereqs (see docs/linux-setup.md / scripts/bootstrap-ubuntu.sh):
+# Prereqs (see design/linux-setup.md / scripts/bootstrap-ubuntu.sh):
 #   - nvidia-drm.modeset=Y
 #   - the NVIDIA GL/EGL userspace (libnvidia-gl-NNN) — provides libEGL_nvidia + the GLVND
 #     vendor JSON; without it wlroots can't init EGL on the GPU and falls back to pixman,