Per-server McpServerFeatures (tools fail-open, resources/prompts
fail-closed) now drive which meta-functions are declared, with
gated_meta_function_prefixes as the single gating seam; read/prompt
declarations land together with their handlers. The server-enablement
sentinel keys on the always-emitted search name so resources-only
servers survive role filtering.
Implements plans/mcp-resources-prompts-design.md §4.4/D7 (T5).
Implements T1 of plans/mcp-resources-prompts-design.md (§4.1, §4.6):
- Replace list_tools(None) with cursor-following list_all_tools() at the
three call sites (start_server catalog build, catalog_items, describe)
so paginating servers no longer silently lose tools past page one.
- Add MCP_READ/MCP_PROMPT prefix constants (declared nowhere yet; wired
in T4/T7) plus centralized helpers MCP_META_FUNCTION_PREFIXES,
is_mcp_meta_function, and mcp_meta_function_names.
- Mechanically replace every hand-rolled 3-prefix starts_with triple
(partition in eval_tool_calls, 3 exclusion triples in
select_enabled_functions, 3 inclusion triples + per-server name
construction in select_enabled_mcp_servers) with the helpers,
preserving the existing lax starts_with matching semantics and the
mcp_invoke_* enablement sentinel (sentinel moves to search in T5).
- Behavior-neutral: dispatch chains keep their 3 arms, emission stays
at exactly 3 meta-functions per server, existing tests unmodified.
- Add unit tests: helper classification, prefix-soundness property,
lax-matching pin, ordered candidate-name construction.
Dark-Alex-17