Added a confluence data center wiki tool (#996)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

documentation/Tools.md

@@ -54,7 +54,7 @@ Keep `Function.DescriptionForLLM` focused on what the tool does. This value is m
 
 A setting offering a fixed choice takes it from an option source — `RequiredChoice` and `OptionalChoice` name a list the app maintains, see `ToolSettingsOptionSources` — or spells its values out in the field's `enum` list, which is how a definition arriving as data offers a choice of its own. The two are mutually exclusive, and `ToolRegistry` rejects a definition that uses both or names an unknown source. Check a stored value in `ValidateConfigurationAsync` either way: it can predate the current list or arrive from an organization's configuration.
 
-When a tool returns data that future messages must only send to providers at or above a specific confidence level, set `ToolExecutionResult.RequiredProviderConfidence`. AI Studio persists the highest requirement reached by the chat and applies it to later provider checks. Provider instances listed in `DataSourceSecuritySettings.TrustedProviderIds` may also continue chats containing data protected this way.
+When a tool returns data that future messages must only send to providers at or above a specific confidence level, set `ToolExecutionResult.RequiredProviderConfidence`. AI Studio persists the highest requirement reached by the chat and applies it to later provider checks. Being listed in `DataSourceSecuritySettings.TrustedProviderIds` does not meet that requirement: the list belongs to data-source security checks, not to confidence. An organization which wants a contractually covered provider to continue such chats raises its level through `DataConfidence.CustomConfidenceScheme`.
 
 ## Security
 
@@ -88,9 +88,13 @@ The prompt-level warning in `systemPromptInstructions` — that everything a too
 
 `web_search` and `read_web_page` both load pages, and so does the `ReadWebContent` component the assistants offer. All three go through `WebPageRetrievalService` — every page AI Studio reads goes through that one service. It validates DNS results and every redirect target before connecting, binds the connection to the validated addresses, caps the response size, and accepts only HTML.
 
-What differs between callers is which targets are acceptable, and that follows from who chose the URL. `web_search` uses the public-only policy and never reads private, loopback, or link-local targets. `read_web_page` may reach an explicitly allowed private host, and only for a High-confidence or configuration-trusted provider. The `ReadWebContent` component sets `TargetChosenByUser`, which lifts the target restrictions entirely: the user typed the address, so their own network and a local server are legitimate. Never set that flag for a URL that reached AI Studio through a model.
+What differs between callers is which targets are acceptable, and that follows from who chose the URL. `web_search` uses the public-only policy and never reads private, loopback, or link-local targets. `read_web_page` may reach an explicitly allowed private host, and only for a High-confidence provider. The `ReadWebContent` component sets `TargetChosenByUser`, which lifts the target restrictions entirely: the user typed the address, so their own network and a local server are legitimate. Never set that flag for a URL that reached AI Studio through a model.
 
-`read_web_page` remains the independent single-URL tool and may use its configured private-host allowlist and operating-system sign-in behavior for allowed HTTPS targets. An allowed private host can only be read by a High-confidence provider or a provider instance listed in `DataSourceSecuritySettings.TrustedProviderIds`.
+`read_web_page` remains the independent single-URL tool and may use its configured private-host allowlist and operating-system sign-in behavior for allowed HTTPS targets. An allowed private host can only be read by a High-confidence provider.
+
+`search_confluence` builds a CQL query for the configured HTTPS Confluence Data Center site's `dosearchsite.action` page and loads it through `WebPageRetrievalService`, the same reader used by `read_web_page`. The model supplies a search phrase and optionally a space key, never a URL or CQL expression. The tool returns the extracted search page as Markdown with links, after truncation and prompt-injection filtering, and lists the search page as its source. Every request, redirects included, must stay within the configured base URL; `WebPageRetrievalOptions.IsTargetAllowed` refuses a redirect before it is followed, so the query never reaches another host. The operating-system sign-in goes to the configured host only when all its addresses are private, the same rule `read_web_page` follows, and a redirect to Confluence's login page is reported as a missing sign-in instead of an empty search. The tool is offered to High-confidence providers only and checks that again before each search, because a lowered tool setting must not let internal wiki content reach a less trusted provider; the result raises the chat's continuing confidence requirement to High. Selecting `search_confluence` also selects `read_web_page` so the model can load a result's full content; the latter tool's private-host allowlist and other availability rules still apply, so a wiki with a private address has to be in that allowlist before any result opens.
+
+Confluence Cloud is not supported yet. It offers neither `dosearchsite.action` as a server-rendered page nor the operating-system sign-in; its search needs Confluence's REST API with an API token instead, which is also the way to stop depending on the HTML of the Data Center search page.
 
 Every successfully retrieved page with readable content is also returned as a structured tool source, using the final URL after redirects and the extracted page title. The provider collects these sources across local tool calls and attaches them to the final response under the separate “Sources used by tools” heading. Failed, blocked, empty, and duplicate retrievals do not add sources — a pattern worth copying for any tool that returns material the user may want to check.