Detect camelCase→PascalCase boundaries between arbitrary prefixes and fixed
local names (tool_calls/invoke/parameter), so that fused forms like
<DSmartToolCalls> are recognized without explicit separator characters.
Also add the underscore-free alias "toolcalls" as a valid DSML local name.
Includes lookalike rejection tests to ensure near-matches like
<DSmartToolCallsExtra> are not falsely accepted.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>