fix(claude): use BIP-39 words for OAuth MCP tool aliases

Replace high-entropy Base32 alias IDs with request-local BIP-39 English
words so weaker models are less likely to drift tool names. Keep a
two-word virtual server plus one-word tool ID, linearly probe wordlist
space on collision without self-overlap, and fall through to unambiguous
longest semantic-suffix recovery after a successful but wrong parse.

Fixes #4916