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>

.gitea/workflows/flatpak.yml

@@ -24,7 +24,7 @@ on:
   push:
     branches: [main]
     # The flatpak is the CLIENT — only rebuild when the client/core/manifest change, not on every
-    # docs/host push (this is a heavy flatpak-builder run). Tags (v*, the client release) build too.
+    # design/host push (this is a heavy flatpak-builder run). Tags (v*, the client release) build too.
     paths:
       - 'clients/linux/**'
       - 'crates/punktfunk-core/**'

.gitea/workflows/windows-drivers-provision.yml

@@ -1,5 +1,5 @@
 # One-shot provisioning of the WDK + cargo-wdk onto the persistent self-hosted windows-amd64 runner, so
-# the all-Rust UMDF drivers can build there (docs/windows-host-rewrite.md, M0). The runner has the base
+# the all-Rust UMDF drivers can build there (design/windows-host-rewrite.md, M0). The runner has the base
 # Windows SDK + MSVC + LLVM + Rust but NOT the WDK (no km/wdf/iddcx headers) or cargo-wdk.
 #
 # Dispatch manually (workflow_dispatch). Idempotent: re-running is a near no-op once provisioned. The

.gitea/workflows/windows-drivers.yml

@@ -1,5 +1,5 @@
 # Windows driver workspace CI — runs on the self-hosted Windows runner (home-windows-1, host mode;
-# label windows-amd64). Part of the Windows-host rewrite (docs/windows-host-rewrite.md, M0).
+# label windows-amd64). Part of the Windows-host rewrite (design/windows-host-rewrite.md, M0).
 #
 # Stage 1 (this file): PROBE the runner's driver toolchain (WDK / EWDK / cargo-make / LLVM / the
 # inf2cat/stampinf/devgen/signtool tools) so we know what's provisioned BEFORE writing driver code,