docs: add Known server-side limitations section to api-ref.md (#1842)

* docs: add Known server-side limitations section

Add a new user-facing section to docs/api-ref.md that lists behaviors
users may hit that are constrained by the Tableau Server REST API
rather than by TSC. Each entry links its tracking issue and notes
where the fix is expected to land. Cross-link the new section from
the top-of-page note, and point at the `Server-Side Enhancement`
label as the live tracker maintained by this repo.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* docs: drop internal work-item IDs and per-bullet fix-scope tag

Public docs on gh-pages will be indexed, so remove the internal
work-item numbers (W-...) from the Known server-side limitations
section along with the paragraph that described what they were.
Also strip the redundant per-bullet "Fix expected: server-side"
tag: the section title already scopes the whole list to server-side
gaps.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Drop On Extract Refresh entry, soften intro and daily-schedule wording

Three fresh-eyes findings:
- Remove the "Subscriptions cannot use On Extract Refresh" entry. The
  REST API's refreshExtractTriggered attribute does support this, and
  TSC support is landing in #1861 (which closes the tracker #1658). The
  entry is about to be factually wrong on both counts.
- Soften the intro: it promised "follow the appropriate issues" for
  every item, but the vf_-silently-dropped entry has no tracker filed.
  New wording says "where filed" so the doc doesn't overpromise.
- Reword the daily-schedules note to describe behavior neutrally
  ("currently runs daily schedules hourly instead") rather than calling
  it a "bug", which reads punchy on a public docs page.

* Drop the vf_ exact-match limitation entry

Opus-5 review found the entry's tracker link (#1431) points at a
closed-not-planned issue; the underlying gap was filed with the
Tableau REST API docs team internally and there's no realistic
timeline for it being tracked back in the TSC repo. Rather than
carry an untracked entry indefinitely, drop it. The behavior claim
(vf_ is exact-match / OR-list only) is now covered by the expanded
docstring on RequestOptions.vf() in #1840.

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jacalata

docs/api-ref.md

@@ -15,7 +15,7 @@ The Tableau Server Client (TSC) is a Python library for the Tableau Server REST
 The TSC API reference is organized by resource. The TSC library is modeled after the REST API. The methods, for example, `workbooks.get()`, correspond to the endpoints for resources, such as [workbooks](#workbooks), [users](#users), [views](#views), and [data sources](#data-sources). The model classes (for example, the [WorkbookItem class](#workbookitem-class) have attributes that represent the fields (`name`, `id`, `owner_id`) that are in the REST API request and response packages, or payloads.
 
 |:---  |
-| **Note:**  Some methods and features provided in the REST API might not be currently available in the TSC library (and in some cases, the opposite is true).  In addition, the same limitations apply to the TSC library that apply to the REST API with respect to resources on Tableau Server and Tableau Cloud. For more information, see the [Tableau Server REST API Reference](https://help.tableau.com/current/api/rest_api/en-us/REST/rest_api_ref.htm).|
+| **Note:**  Some methods and features provided in the REST API might not be currently available in the TSC library (and in some cases, the opposite is true).  In addition, the same limitations apply to the TSC library that apply to the REST API with respect to resources on Tableau Server and Tableau Cloud. For more information, see the [Tableau Server REST API Reference](https://help.tableau.com/current/api/rest_api/en-us/REST/rest_api_ref.htm). See also [Known server-side limitations](#known-server-side-limitations) below for behaviors that TSC cannot work around because they are constrained by the Tableau Server REST API itself.|
 
 
 
@@ -10974,3 +10974,35 @@ for wb in finance_workbooks:
 <br>
 <br>
 
+---
+
+## Known server-side limitations
+
+Some behaviors you may hit while using TSC are not bugs in the TSC library. They are limitations of the Tableau Server REST API itself, and cannot be fixed in TSC alone. This section lists known server-side gaps so you can identify them quickly and follow the tracking issues where filed.
+
+For the live, maintainer-updated view of these issues, filter open issues in this repository by the [`Server-Side Enhancement`](https://github.com/tableau/server-client-python/labels/Server-Side%20Enhancement) label.
+
+Every item in this list requires a change in Tableau Server / Tableau Cloud before TSC can expose the behavior.
+
+<br>
+
+**`vf_` view filter is silently dropped when the server-side view already has an operator-based filter**
+: If the underlying view definition includes a filter that uses an operator (for example, a range filter), a client-supplied `vf_` value on that same field can be silently ignored rather than layered on top. There is no error surfaced through the REST API.
+
+<br>
+
+**Daily extract-refresh schedules cannot be created via the REST API on Tableau Cloud**
+: Creating an extract-refresh task on a daily schedule fails through the REST API (returns a 500), and the underlying Cloud scheduler currently runs daily schedules hourly instead. Tracked in [#1508](https://github.com/tableau/server-client-python/issues/1508).
+
+<br>
+
+**Flow thumbnail image is not generated when a flow is published via the REST API**
+: A flow published through the REST API (and therefore through TSC's `flows.publish(...)`) is stored without a thumbnail image, whereas the same flow uploaded through the Tableau Prep UI receives one. Tracked in [#1537](https://github.com/tableau/server-client-python/issues/1537).
+
+<br>
+
+If you believe you have found another server-side limitation, please open an issue and mention this section so a maintainer can apply the `Server-Side Enhancement` label and add it to the list above.
+
+<br>
+<br>
+