M2: naming/curation wall verification batch (C17 C18 C19 C20) #22

Source: multi-agent review of PR #16, all UNVERIFIED-FINDER — verify first, then fix what holds. 2026-08-13. M-anchor: M2 — the List* verb rule already lands in OperationNamePolicy and curation grows with the first breadth batch; verify these inside that work.

• C18 (highest priority of the four — public generated naming): OperationNamePolicy.Subject filters every post-group segment equal to the HTTP method (OperationNamePolicy.cs:44-49) — a value filter, not a structural verb position. A future operation whose resource subject legitimately contains the verb word loses that segment (v2.cache.get.entry → GetEntryAsync) and can collide with another generated name. Fix direction: strip only the structural verb position; pin fixtures where a later segment equals the verb.
• C17: mechanically derived payload names never pass through identifier validation — ValidateEnvelopeNames covers curated overrides only (CurationValidator.cs:128-150); binder checks only the response-spine blacklist (OperationPlanBinder.cs:345-356). Note: the finder's ToPascalCase("2fa") example is stale (CSharpNamePolicy.cs:23-26 prefixes _), but keyword/punctuation/empty-transform cases remain unvalidated. Fix: one identifier validator after derivation for every final payload name, curated or mechanical; coordinate with C20.
• C19: ReservedPayloadNames is a four-string blacklist (Error/IsError/RawBody/Status, OperationPlanBinder.cs:17,345-356); record-generated/inherited members (PrintMembers, Equals, GetHashCode) are unguarded — verify against the exact emitted record shape, then replace the ad hoc list with a centralized response-member collision rule tested as a whole.
• C20: CSharpNamePolicy.IsValidIdentifier is a char predicate only (CSharpNamePolicy.cs:37-45) — C# keywords (class, event, namespace) pass and reach emitters bare. Fix: Roslyn keyword classification; fail-closed posture favors refusal over escaping. Tests across reserved + contextual keywords per curated name category.