mcp/client: add list_all_* helpers with pagination safety guards

[dongjiang1989]

The Python SDK lacks auto-pagination helpers for the four list verbs (tools/list, resources/list, resources/templates/list, prompts/list). Callers must write their own cursor-draining loops, and those loops have no protection against infinite pagination or cursor cycles.

The TypeScript SDK already provides this via _listAllPages with a listMaxPages cap and cursor cycle detection (see typescript-sdk#2336). The Go SDK is getting the same guards in go-sdk#1110. This PR brings the Python SDK to parity.

What changed

Four new methods on the high-level Client:

awaitclient.list_all_tools() ->ListToolsResultawaitclient.list_all_resources() ->ListResourcesResultawaitclient.list_all_resource_templates() ->ListResourceTemplatesResultawaitclient.list_all_prompts() ->ListPromptsResult

Each drains all pages into a single aggregated result via a shared
_drain_all_pages helper with two safety guards:

1. Page cap: Client.list_max_pages (default 64, matching the TS
   SDK's DEFAULT_LIST_MAX_PAGES). Exceeding the cap raises
   PaginationExceededError. Setting to 0 or a negative value
   disables the cap (unlimited).

2. Cursor cycle detection: a seen set tracks all cursors
   returned by the server. A repeated cursor raises
   CursorCycleError, preventing infinite loops from buggy servers.

Both exception types are exported from mcp.client.

Configuration

# Default: 64 pagesclient=Client(server)
# Custom capclient=Client(server, list_max_pages=100)
# Unlimitedclient=Client(server, list_max_pages=0)

How Has This Been Tested

9 new tests in tests/client/test_list_all_pagination.py:

• Normal multi-item drain for all 4 verbs
• Empty server returns empty lists
• PaginationExceededError when cap exceeded
• CursorCycleError on repeated cursor
• Unlimited mode (list_max_pages=0)
• Terminal cursor stripping (next_cursor is None)

All 709 existing client tests continue to pass. Lint (ruff check)
and type check (pyright) are clean.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

[cubic-dev-ai]

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