feat(website): add the offline downloads guide with a reusable content disclaimer

New guide at /blog/offline-downloads-guide/: what the desktop download manager
can save, choosing the folder, downloading a movie, episodes and seasons,
following the queue (pause, resume, automatic reconnects), the offline
library, and the Needs attention states, with a nine-question FAQ. The prose
frames the feature as offline viewing of content the reader already streams
and defers legality to the provider's terms and local law.

ContentDisclaimer.astro carries that notice in a general and an offline
variant so later guides reuse it instead of rewording it.

The three screenshots are mock-backed captures. The Xtream mock's marketing
scenario now serves movie and episode stream URLs from generated local bytes
(downloadStreamFixture: 'local-media'), because the capture's network gate
rejects the public HLS stub every other scenario redirects to; the capture
stubs Electron's folder dialog so "Change Folder" authorizes a folder inside
the isolated data dir rather than the real OS Downloads folder; two new setup
actions queue a movie and two episodes and open the manager and the offline
detail.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

CLAUDE.md

@@ -350,7 +350,7 @@ This is an Nx monorepo with the following structure:
 - **apps/electron-backend-e2e** - Playwright E2E tests against the Electron app
 - **apps/stalker-mock-server** - Mock Stalker/Ministra portal for dev and E2E
 - **apps/xtream-mock-server** - Mock Xtream Codes API for dev and E2E
-- **apps/website** - Astro + Tailwind landing page, blog (guides carry `faq:` frontmatter → FAQPage JSON-LD; tags are a closed vocabulary in `src/lib/blog-tags.ts` enforced by the collection schema, each with a `/blog/tag/<tag>/` hub), per-OS download landing pages (`/download/`, `/download/{windows,macos,linux}/`) plus the Docker page (`/download/docker/`) feature landing pages (`/features/`, registry in `src/lib/features.ts`) and comparison pages (`/compare/`, registry in `src/lib/comparisons.ts`, comparing IPTVnator's own options rather than other products); direct asset links are resolved at build time from the GitHub Releases API with a `package.json` fallback (`src/lib/downloads.ts`, see `apps/website/README.md`)
+- **apps/website** - Astro + Tailwind landing page, blog (guides carry `faq:` frontmatter → FAQPage JSON-LD and open with `src/components/blog/ContentDisclaimer.astro`, whose `offline` variant is mandatory for posts about downloads or recordings; tags are a closed vocabulary in `src/lib/blog-tags.ts` enforced by the collection schema, each with a `/blog/tag/<tag>/` hub), per-OS download landing pages (`/download/`, `/download/{windows,macos,linux}/`) plus the Docker page (`/download/docker/`) feature landing pages (`/features/`, registry in `src/lib/features.ts`) and comparison pages (`/compare/`, registry in `src/lib/comparisons.ts`, comparing IPTVnator's own options rather than other products); direct asset links are resolved at build time from the GitHub Releases API with a `package.json` fallback (`src/lib/downloads.ts`, see `apps/website/README.md`)
 - **libs/** - Shared libraries:
     - **epg/data-access** - EPG services, runtime bridge, program normalization
     - **m3u-state** - NgRx state management for M3U playlists