feat: disable capabilities by model provider (#19442)

## Why

Unsupported features must fail closed and Codex must not expose
OpenAI-hosted fallback paths when the active provider cannot support
them. In practice, Bedrock should not surface app connectors, MCP
servers, tool search/suggestions, image generation, web search, or JS
REPL until those paths are explicitly supported for that provider.

This PR moves that decision into provider-owned capability metadata
instead of scattering Bedrock-specific checks across callers.

## What changed

- Adds `ProviderCapabilities` to `codex-model-provider`, with default
support for existing providers and a Bedrock override that disables
unsupported launch surfaces.
- Adds `ToolCapabilityBounds` to `codex-tools` so provider capability
limits can clamp otherwise-enabled tool config.
- Applies capability bounds when building session and review-thread tool
config.
- Routes MCP/app connector configuration through
`McpManager::mcp_config`, which filters configured MCP servers and app
connectors based on the active provider.
- Updates app-server MCP list/read paths to use the filtered MCP config.
- Adds coverage for default provider capabilities, Bedrock disabled
capabilities, and optional tool-surface clamping.

## Testing

built locally and verified that bedrock responses api now return without
errors calling unsupported tools.

codex-rs/core/src/session/review.rs

@@ -25,6 +25,7 @@ pub(super) async fn spawn_review_thread(
     let _ = review_features.disable(Feature::WebSearchCached);
     let review_web_search_mode = WebSearchMode::Disabled;
     let goal_tools_supported = !config.ephemeral && parent_turn_context.tools_config.goal_tools;
+    let provider_capabilities = parent_turn_context.provider.capabilities();
     let tools_config = ToolsConfig::new(&ToolsConfigParams {
         model_info: &review_model_info,
         available_models: &sess
@@ -41,6 +42,9 @@ pub(super) async fn spawn_review_thread(
         permission_profile: &parent_turn_context.permission_profile,
         windows_sandbox_level: parent_turn_context.windows_sandbox_level,
     })
+    .with_namespace_tools_capability(provider_capabilities.namespace_tools)
+    .with_image_generation_capability(provider_capabilities.image_generation)
+    .with_web_search_capability(provider_capabilities.web_search)
     .with_unified_exec_shell_mode_for_session(
         crate::tools::spec::tool_user_shell_type(sess.services.user_shell.as_ref()),
         sess.services.shell_zsh_path.as_ref(),

codex-rs/core/src/session/turn_context.rs

@@ -173,6 +173,7 @@ impl TurnContext {
             /*developer_instructions*/ None,
         );
         let features = self.features.clone();
+        let provider_capabilities = self.provider.capabilities();
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
             model_info: &model_info,
             available_models: &models_manager
@@ -187,6 +188,9 @@ impl TurnContext {
             permission_profile: &self.permission_profile,
             windows_sandbox_level: self.windows_sandbox_level,
         })
+        .with_namespace_tools_capability(provider_capabilities.namespace_tools)
+        .with_image_generation_capability(provider_capabilities.image_generation)
+        .with_web_search_capability(provider_capabilities.web_search)
         .with_unified_exec_shell_mode(self.tools_config.unified_exec_shell_mode.clone())
         .with_web_search_config(self.tools_config.web_search_config.clone())
         .with_allow_login_shell(self.tools_config.allow_login_shell)
@@ -448,6 +452,7 @@ impl Session {
             image_generation_tool_auth_allowed(auth_manager.as_deref());
         let auth_manager_for_context = auth_manager.clone();
         let provider_for_context = create_model_provider(provider, auth_manager);
+        let provider_capabilities = provider_for_context.capabilities();
         let session_telemetry_for_context = session_telemetry;
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
             model_info: &model_info,
@@ -459,6 +464,9 @@ impl Session {
             permission_profile: &session_configuration.permission_profile(),
             windows_sandbox_level: session_configuration.windows_sandbox_level,
         })
+        .with_namespace_tools_capability(provider_capabilities.namespace_tools)
+        .with_image_generation_capability(provider_capabilities.image_generation)
+        .with_web_search_capability(provider_capabilities.web_search)
         .with_unified_exec_shell_mode_for_session(
             crate::tools::spec::tool_user_shell_type(user_shell),
             shell_zsh_path,