feat(theme): restore Base Nova OpenAPI surfaces

[aeei]

Summary

• restore the complete OpenAPI info/category/operation/schema/explorer surface inside the shared Base Nova shell
• replace legacy OpenAPI controls with the repository-owned Base Nova primitives, including tabs, accordion, select, cards, badges, table, dropdown menu, dialog, spinner, and separator
• add a configurable containerMaxWidth theme option while preserving the 90rem default for navbar, docs shell, footer, media viewer, and OpenAPI dialogs
• align homepage, regular docs, generated categories, sidebar rail, TOC, cards, and pagination to one stable horizontal/vertical guide
• make authentication tables and long content responsive without document-level overflow
• prevent recursive schema/search-index stack overflows while preserving current schema normalization
• bump @aeei/docusaurus-theme to 0.1.11

Visual acceptance

User reviewed and approved the local desktop/mobile × light/dark screenshots before this commit.

• 20 full-page states: homepage, category, info, operation, schema
• all integer widths 320..3840, light/dark, representative normal/category/info/operation routes
• zero shell geometry or document-overflow failures
• default 1920px viewport shell: 1440px, centered at x=240
• shared content guide: x=320 at 1280, x=400 at 1440, x=640 at 1920
• generated category heading/card/paginator gaps: 24px

Validation

• yarn test --runInBand — 36 suites, 251 tests, 35 snapshots
• yarn build-packages — 4 packages
• demo production build
• docs-starter production build
• isolated npm tarball install/build with generated local search index
• theme Playwright — 26 passed
• OpenAPI/demo Playwright — 5 passed
• focused Prettier, LSP/type diagnostics, git diff --check
• independent review — no actionable findings

Artifact

• package: @aeei/docusaurus-theme@0.1.11
• exact merge source: c0c96f9f4fa94c200289b37a8d7ede79097f90f6
• local verification archive: aeei-docusaurus-theme-0.1.11.tgz
• SHA-256: 1958e15fde075b8d075d199dcc598ecfc8b5b85cf5aed7b90636d165726c0ef7
• SHA-512 integrity: sha512-fzZ6bGQtwfhZAtzAp/wOrFULxksZcB11OCwLJrHqA0fuMsf0ugmhptJk2VTRXOd+XGn5SCx7LnaLTEx2K7hDWQ==

No npm publish or deployment is performed by this PR.