Neutralize internal Anthropic prose in explanatory comments (#357)

This is a small prose-only follow-up that rewrites clearly internal or
explanatory Anthropic comment language to neutral wording in a handful of
high-confidence files. It avoids runtime strings, flags, command labels,
protocol identifiers, and provider-facing references.

Constraint: Keep this pass narrowly scoped to comments/documentation only
Rejected: Broader Anthropic comment sweep across functional API/protocol references | too ambiguous for a safe prose-only PR
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Leave functional Anthropic references (API behavior, SDKs, URLs, provider labels, protocol docs) for separate reviewed passes
Tested: bun run build
Tested: bun run smoke
Tested: bun run verify:privacy
Tested: bun run test:provider
Tested: bun run test:provider-recommendation
Not-tested: Full repo typecheck (upstream baseline remains noisy)

Co-authored-by: anandh8x <test@example.com>

src/utils/attachments.ts

@@ -2641,7 +2641,7 @@ let suppressNext = false
 const FILTERED_LISTING_MAX = 30
 
 /**
- * Filter skills to bundled (Anthropic-curated) + MCP (user-connected) only.
+ * Filter skills to bundled + MCP (user-connected) only.
  * Used when skill-search is enabled to resolve the turn-0 gap for subagents:
  * these sources are small, intent-signaled, and won't hit the truncation budget.
  * User/project/plugin skills (the long tail — 200+) go through discovery instead.