Add column labels, selectionless actions, Apple-like design refresh

[vsdudakov]

Features

• Column labels: new ModelAdmin.list_display_labels attribute ({"field": "Header"}) to override or translate auto-generated list-page column titles. Data binding, sorting and filtering stay keyed by the field name.
• Actions without selection: @action(requires_selection=False) enables the Apply button without selecting rows; the handler receives an empty ids list and should treat it as "all objects". Default behavior is unchanged.

Frontend

• Apple-like design refresh: frosted-glass sticky header with hairline borders — the configured primary_color now serves as the accent (buttons, links, menu selection) instead of the header background; larger corner radii, softer diffuse shadows, #f5f5f7/#161617 layout backgrounds, tighter letter spacing, transparent table headers. The rich-text editor accent follows primary_color instead of a hardcoded teal. Verified visually on the fastapi_sqlalchemy example in light and dark modes.
• Dependencies: antd 6.5.1, i18next 26, react-i18next 17, vite 8, jsdom 29, TypeScript 6.0, vitest 4.1.10, eslint 10.7. Added quill-delta to satisfy a peer dependency; removed deprecated baseUrl from tsconfig.json (TypeScript is kept at 6.0 because typescript-eslint declares peer <6.1.0).

Backend

• uv.lock refreshed within the declared dependency ranges (asgiref 3.12, django 6.0.7, yara-orm 1.14.4, …); no changes to the supported ranges in pyproject.toml.

Docs & tests

• list_display_labels and requires_selection documented in the model-admins guide, API reference and settings guide; changelog updated.
• New tests: decorator metadata, schema generation (label + requires_selection), column title fallback with intact sorting/filtering, Apply button state without selection.

Checks

• pytest: 2075 passed, coverage 100% (gate)
• vitest: 247 passed, coverage gate green
• ruff + ruff format + ty, eslint + biome: clean
• yarn build, mkdocs build --strict: clean