Fix edit prediction disablement with "disable_ai": true setting (#35513)

Even after #35327 edit predictions were still being queried and shown
after setting `"disable_ai": true`

Also moves `DisableAiSettings` to the `project` crate so that it gets
included in tests via existing use of `Project::init_settings(cx)`.

Release Notes:

- Fixed `"disable_ai": true` setting disabling edit predictions.

crates/agent_ui/src/agent_panel.rs

@@ -43,7 +43,7 @@ use anyhow::{Result, anyhow};
 use assistant_context::{AssistantContext, ContextEvent, ContextSummary};
 use assistant_slash_command::SlashCommandWorkingSet;
 use assistant_tool::ToolWorkingSet;
-use client::{DisableAiSettings, UserStore, zed_urls};
+use client::{UserStore, zed_urls};
 use cloud_llm_client::{CompletionIntent, Plan, UsageLimit};
 use editor::{Anchor, AnchorRangeExt as _, Editor, EditorEvent, MultiBuffer};
 use feature_flags::{self, FeatureFlagAppExt};
@@ -58,7 +58,7 @@ use language::LanguageRegistry;
 use language_model::{
     ConfigurationError, ConfiguredModel, LanguageModelProviderTosView, LanguageModelRegistry,
 };
-use project::{Project, ProjectPath, Worktree};
+use project::{DisableAiSettings, Project, ProjectPath, Worktree};
 use prompt_store::{PromptBuilder, PromptStore, UserPromptId};
 use rules_library::{RulesLibrary, open_rules_library};
 use search::{BufferSearchBar, buffer_search};