Remove 3.x-era compatibility shims (#4661)

* Remove 3.x-era compatibility shims

* Require response_type in ctx.elicit()

* Name the utilities path for the two non-re-exported auth helpers

* Point sampling handler migration at its submodule

dev-docs/v4-notes/change-register.md

@@ -567,6 +567,10 @@ The `_REMOVED_KWARGS` constructor shim (which raises helpful `TypeError`s for kw
 - **Tool-level `serializer` parameter** — removed from `@tool` / `mcp.tool()`, `Tool.from_function`, `Tool.from_tool`, `TransformedTool.from_tool`, the OpenAPI `OpenAPITool`, and the `mcp_mixin` tool decorator. Return a `ToolResult` from your tool for full control over serialization instead (see [Custom Serialization](https://gofastmcp.com/servers/tools#custom-serialization)). The server-level `tool_serializer` constructor kwarg was already removed in 3.0.
 - **Tool `exclude_args` parameter** — removed from the tool decorator and its plumbing (`ParsedFunction.from_function`, `Tool.from_function`, `mcp.tool()`). Use dependency injection with `Depends()` to hide parameters from the tool schema instead.
 - **`decorator_mode` setting** (`FASTMCP_DECORATOR_MODE`) and its `"object"` mode — removed. Decorators always return the original function with metadata attached; the object-returning machinery is gone. Access component objects through the server (e.g. `await mcp.get_tool("name")`) rather than the decorated function.
-- **Component-import compatibility shims** — the `__getattr__` shims that re-exported `FunctionTool` / `ParsedFunction` / `tool` from `fastmcp.tools.tool`, `FunctionResource` / `resource` from `fastmcp.resources.resource`, and `FunctionPrompt` / `prompt` from `fastmcp.prompts.prompt` are removed. Import these from their canonical modules (`fastmcp.tools.function_tool`, `fastmcp.resources.function_resource`, `fastmcp.prompts.function_prompt`) instead.
+- **Component-import compatibility shims** — Breaking. `fastmcp.tools.tool`, `fastmcp.resources.resource`, and `fastmcp.prompts.prompt` no longer exist as modules. Two separate mechanisms kept them alive and both are now gone: the `__getattr__` shims that re-exported `FunctionTool` / `ParsedFunction` / `tool`, `FunctionResource` / `resource`, and `FunctionPrompt` / `prompt`; and the `sys.modules` aliases that pointed each old module name at its renamed `base.py`. Import the component types from the package itself — `from fastmcp.tools import Tool, ToolResult` — and the function-backed classes from their canonical modules (`fastmcp.tools.function_tool`, `fastmcp.resources.function_resource`, `fastmcp.prompts.function_prompt`).
+- **`fastmcp.experimental.sampling`** and **`fastmcp.experimental.sampling.handlers`** (2.x-era re-export shims) — Breaking. These aliased the client-side sampling handlers without warning. Import from `fastmcp.client.sampling.handlers.openai` instead. Note this is unrelated to the SEP-2577 removal of *server-initiated* sampling: a FastMCP client still answers a legacy-era server's sampling requests, so `Client(sampling_handler=...)` and the Anthropic / OpenAI / Google GenAI handlers under `fastmcp.client.sampling.handlers` remain fully supported.
+- **`fastmcp.server.auth.authorization`** (3.0-era re-export shim) — Breaking. The module was a pass-through sitting between the `fastmcp.server.auth` package and the real implementation in `fastmcp.utilities.authorization`, and FastMCP's own middleware and local-provider decorators imported through it. Everything internal now imports from `fastmcp.utilities.authorization` directly. The documented public path is unchanged: `from fastmcp.server.auth import require_scopes, require_roles, restrict_tag, run_auth_checks, AuthCheck, AuthContext`. Two names the old module also exported — `run_auth_checks_with_shortfall` and `scope_requirements` — are *not* re-exported from `fastmcp.server.auth` and must be imported from `fastmcp.utilities.authorization`. They are middleware plumbing with no documented user-facing use, so they were deliberately not widened onto the auth package's surface; the upgrade guide names the utilities path for them explicitly.
+- **`SkillsProvider`** (3.0-era rename alias) — Breaking. Use `SkillsDirectoryProvider` from `fastmcp.server.providers.skills`. The alias was also re-exported from `fastmcp.server.providers`; both are gone.
+- **`ctx.elicit()` without `response_type`** (deprecated 3.2, warned through 3.4.4) — Breaking. The parameter is now required, and passing `None` explicitly raises `TypeError`. The empty-object schema it produced was ambiguous under the MCP spec and left some clients (e.g. VS Code) rendering an empty, non-functional form. Pass a type describing the data you expect back; `bool` covers confirmations. This is the server-authoring API only — the *client* elicitation handler still receives `response_type=None` for URL requests and for empty schemas sent by other servers, which is unchanged.
 
 *Verify:* deletions of `fastmcp_slim/fastmcp/server/proxy.py`, `fastmcp_slim/fastmcp/server/openapi/`, `fastmcp_slim/fastmcp/experimental/server/openapi/`, `fastmcp_slim/fastmcp/experimental/utilities/openapi/`, `fastmcp_slim/fastmcp/server/apps.py`, `fastmcp_slim/fastmcp/server/app.py`; the removed classes in `fastmcp_slim/fastmcp/server/middleware/tool_injection.py`; the removed parameter in `fastmcp_slim/fastmcp/client/transports/http.py`; `fastmcp_slim/fastmcp/server/server.py`; `fastmcp_slim/fastmcp/tools/base.py`, `tools/function_tool.py`, `tools/tool_transform.py`, `tools/function_parsing.py`; `fastmcp_slim/fastmcp/settings.py`, `resources/function_resource.py`, `prompts/function_prompt.py`, and the local-provider decorators; `resources/base.py`, `prompts/base.py`.