feat: add Desktop App 7.1.0 release notes

[DeepDiver1975]

Adds the Desktop App 7.1.0 release notes entry, coinciding with the desktop docs 7.1
version going live (see owncloud/docs#5107 and owncloud/docs-client-desktop#720).

Changes

• New == Desktop App 7.1.0 section at the top of desktop_release_notes.adoc, following the
  existing per-version format (General + GitHub changelog link).
• A NOTE admonition documenting that there is no public 7.0 release — 7.0 was an
  internal-only build used for cross-team integration and release-process validation, so the
  public 7.x line starts at 7.1.0. This explains the version jump from 6.0.x to 7.1.0.

Verification

• Built locally with npm run antora-local (Node 22): exit 0, no errors referencing
  desktop_release_notes.adoc. The pre-existing cross-component xref errors in
  client_releases.adoc/index.adoc are expected in the standalone test build
  (failure_level: none) and unrelated to this change.
• Confirmed the 7.1.0 entry and the 7.0 note render correctly in public/desktop_release_notes.html.

🤖 Generated with Claude Code

[DeepDiver1975]

🤖 Automated review by Claude Code review agent.

Overview

This PR adds a == Desktop App 7.1.0 section to modules/ROOT/pages/desktop_release_notes.adoc, following the existing per-version format (General + GitHub changelog link), plus two admonitions: an IMPORTANT block stating the 7 series is oCIS-only, and a NOTE explaining that 7.0 was internal-only so the public line jumps from 6.0.x to 7.1.0. Net +20/-0 lines, one file.

I verified the claims against the upstream owncloud/client repository:

• 7.1.0 is a real release. Tag v7.1.0 exists (created 2026-06-08) and CHANGELOG.md@v7.1.0 has "Changelog for 7.1.0 (2026-06-08)". Good.
• The oCIS-only claim is substantiated. The 7.1.0 changelog contains Change - Remove support for ownCloud Server (OC10): #12167, which backs the IMPORTANT note.

The change is low-risk (additive, no nav/antora changes needed since it edits an existing page), but there are a few accuracy/completeness items worth addressing before merge.

Code quality / style

• AsciiDoc syntax is correct: [discrete], [IMPORTANT]/[NOTE] delimited blocks (====), the hard line break +, and the {desktop-releases-url}v7.1.0[...] attribute reference all match the existing entries in this file. The new section sits correctly above 6.0.3 (descending version order). No rendering concern.
• The window=_blank link macro syntax matches the surrounding entries — consistent.

Specific suggestions

1. Missing "Notable Changes" subsection — completeness. Every other entry in this file (6.0.0–6.0.3) carries a [discrete] === Notable Changes / Notable Fixes bullet list. The 7.1.0 entry has only the General paragraph and the changelog link, despite 7.1.0 being the largest release in this file by far. The upstream changelog summary highlights items that users genuinely need to know before upgrading, e.g.:

   • Removal of the command-line sync client (#12162)
   • Removal of bandwidth throttling controls (#12335)
   • Removal of the suffix VFS plugin (#12174)
   • macOS 13 is now the minimum (#12245); Qt 6.8 minimum (#12270)
   • New account setup wizard (#12189) and redesigned account/folder management view (#12399)
   • Group policy / system-based configuration (#12367)

   Consider adding a Notable Changes list so the entry matches the established format and surfaces the breaking removals (CLI client, throttling) that affect existing users.

2. "version 10 or 11" vs. changelog wording. The IMPORTANT note says "ownCloud Classic (Server) version 10 or 11". The upstream changelog only references removal of OC10 support (#12167); it does not mention an "11". Please confirm "11" is intentional/correct — if there is no ownCloud Server 11 in this context, drop it to avoid introducing an inaccuracy.

Potential issues / risks

1. No published GitHub Release for the tag (link target). GET /repos/owncloud/client/releases/tags/v7.1.0 returns 404 — only the git tag exists, not a published Release. The doc links to https://github.com/owncloud/client/releases/tag/v7.1.0. GitHub's releases/tag/<tag> URL still resolves to a tag page even without a published release, so the link is not broken — but the "full change log" it promises will be sparse compared to the prior entries (whose tags have full release bodies). This reinforces suggestion #1: if the Release page is thin, the inline Notable Changes list becomes the user's primary changelog. Worth confirming a GitHub Release will be published for v7.1.0.

2. "security fixes" wording in General. The boilerplate General paragraph ("...new features and security fixes") is copied verbatim from prior entries. The 7.1.0 changelog summary lists bugfixes and changes but no explicitly labelled security fix (unlike 6.0.2/6.0.3 which call out CVEs). Minor — the boilerplate is consistent with the file's style, but flagging in case you want to avoid implying a security release where none is documented.

3. Nav (informational, not a blocker). desktop_release_notes.adoc is not referenced from modules/ROOT/nav.adoc; this is pre-existing and unrelated to this PR, which only appends a section to an existing page. No action needed here.

Overall: accurate framing, clean AsciiDoc, correctly placed. The main gap is the absent Notable Changes list given the size of this release; the "version 11" wording is the one factual item I'd double-check.