Add spector case for extensible enum with special word member names

[Copilot]

• Add extensible enum (union) with 33 special word member names to special-words/main.tsp
• Simplify to single @put operation per reviewer feedback
• Add Enum return type so mock API echoes back the sent value
• Add handler to dynamically extract request body and echo it back in response
• Remove explicit contentType headers (default application/json is sufficient)
• Remove redundant @doc decorators from union definition for consistency with rest of file
• Regenerate spec-summary
• Build validated (61 scenarios pass)
• Format, code review, and security scan clean

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[msyyc]

@copilot check all changes of the PR to make sure they are consistent.

[Copilot]

@copilot check all changes of the PR to make sure they are consistent.

Reviewed all changes for consistency in f70bb68. Found and fixed one issue: the union Enum definition had redundant @doc decorators on the union itself and on every member, which was inconsistent with the rest of the file (no other types use @doc). Removed them, keeping just the JSDoc comment. All three changed files are now consistent:

• main.tsp: Union uses JSDoc only (matching existing models/operations), single @put op with Enum input/output, no explicit contentType
• mockapi.ts: Handler echoes req.body back in response, matching the TSP contract
• spec-summary.md: Auto-generated, matches the scenario definition

Build passes with 61 valid scenarios.