docs: normalize legacy server product name to "ownCloud Classic" (#256)

Rename the legacy ownCloud server product to its canonical name
"ownCloud Classic" across all user-facing documentation text. The
version (10/11) is kept only as trailing information where relevant
(e.g. "ownCloud Classic 10").

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

Scope is limited to prose, headings and link display text.
xref/include targets, module slugs (classic_ui, oc10-app), URLs,
attribute names (e.g. oc10-api-url), image paths, anchors, and the
new product names (ownCloud Infinite Scale / oCIS) are unchanged.

Verified: every URL/xref target byte-identical and oCIS/Infinite
Scale occurrences unchanged.

Part of owncloud/docs#5111

Signed-off-by: Thomas Müller <1005065+DeepDiver1975@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: DeepDiver1975

modules/ROOT/pages/accounts.adoc

@@ -18,7 +18,7 @@ Then, click btn:[Manage accounts]. From there, you can see all of the currently
 
 == Adding Accounts
 
-To add a new account is identical to creating the first account. Click btn:[Add account], and then follow the instructions in xref:connecting.adoc#connecting[Connecting to Your ownCloud Server].
+To add a new account is identical to creating the first account. Click btn:[Add account], and then follow the instructions in xref:connecting.adoc#connecting[Connecting to Your ownCloud Classic].
 
 == Viewing Accounts
 

modules/ROOT/pages/appendices/troubleshooting.adoc

@@ -83,7 +83,7 @@ D: 2023-09-04 09:57:38:562(LogBuilder.kt:38) .logHttp()[Network, response] [body
 | HTTP bodies (JSON, XML)
 |===
 
-### ownCloud Server Log File
+### ownCloud Classic Log File
 
 The ownCloud server also maintains an ownCloud specific log file. This log file must be enabled through the ownCloud Administration page. On that page, you can adjust the log level. We recommend that when setting the log file level that you set it to a verbose level like `Debug` or `Info`.
 

modules/ROOT/pages/faq.adoc

@@ -13,7 +13,7 @@
 
 == Usage
 
-=== Minimum ownCloud Server Version
+=== Minimum ownCloud Classic Version
 
 ownCloud Android app 2.15 has minimum requirement of ownCloud server 10.0 or later.