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>

packaging/windows/drivers/Cargo.toml

@@ -1,6 +1,6 @@
 # Unified in-tree workspace for punktfunk's all-Rust UMDF drivers, on microsoft/windows-drivers-rs
 # (crates.io wdk/wdk-sys/wdk-build — NOT the dev-box ../../crates/wdk* path-deps). Part of the
-# Windows-host rewrite (docs/windows-host-rewrite.md, M1). pf-vdisplay + the gamepad drivers move here.
+# Windows-host rewrite (design/windows-host-rewrite.md, M1). pf-vdisplay + the gamepad drivers move here.
 #
 # Separate from the main cargo workspace (own [workspace] root) because driver crates are cdylibs built
 # with the WDK toolchain (cargo-wdk / wdk-build) on Windows only. Path-deps the shared ABI crate