docs: normalize legacy server product name to "ownCloud Classic" (12.6)

[DeepDiver1975]

What

Normalizes the legacy ownCloud server product to its canonical name ownCloud Classic across all user-facing documentation in this repo. Version (10/11) is retained only as trailing information where relevant (e.g. "ownCloud Classic 10").

Normalized: ownCloud Server, owncloud Server, ownCloud Classic Server, and bare ownCloud 10/11.

Why

Part of owncloud/docs#5111 — a coordinated, docs-only rebranding so the legacy product is consistently named ownCloud Classic across the owncloud / owncloud-docker orgs. Reference implementation: owncloud/docs-main#187.

Out of scope (intentionally untouched)

• xref:/include:: targets, module slugs (classic_ui, oc10-app), URLs, attribute names (e.g. oc10-api-url), image paths, anchors
• The new product names: ownCloud Infinite Scale / oCIS

Verification

• All target variants normalized; only prose / headings / link display text changed.
• Every xref/include/URL target byte-for-byte identical before/after.
• oCIS / Infinite Scale occurrence count unchanged.
• No internal xref depends on any heading whose auto-generated anchor changes.

Reviewer checklist

• No xref targets / module slugs / URLs altered
• oCIS / Infinite Scale untouched
• Version shown only as additional info ("ownCloud Classic 10")

🤖 Generated with Claude Code

[DeepDiver1975]

🤖 Automated review by Claude Code review agent.

Reviewed the diff for branch docs/backport-owncloud-classic-12.6 (base 12.6).

Verdict: LGTM (prose-only). The change touches a single file (modules/ROOT/pages/faq.adoc) and is a pure display-text normalization, ownCloud Server → ownCloud Classic, on two lines:

• A === section heading.
• One body sentence.

No non-prose targets were altered: no xref targets, URLs, :page-aliases:, slugs, file names, attribute names, or code literals. The {ios-legacy-appstore-url} attribute reference and the [App Store] xref label are untouched.

Non-blocking note: renaming the === heading changes its auto-generated anchor ID (_compatibility_with_owncloud_server_... → ..._classic_...). If any page cross-references this section by its auto ID, that xref would break. The diff shows no in-repo references to the old anchor, so this is informational only and consistent across the sibling backports (#285, #287).

CHANGELOG: n-a (this repo has no changelog).
Checks: Build documentation + lint both passing.