fix(i18n): drop generic concept words from DEFAULT_PROTECTED_TERMS fallback (#224)

DEFAULT_PROTECTED_TERMS is the Gemini "keep-English" fallback used by
getKeepEnglishTerms() only when a locale has no _protected keys. It still listed
skill, Subagent, Enterprise, Personal, Plugin, and Dispatch — generic concept
words that PR #218 deliberately REMOVED from the per-locale _protected blocks
because they are translated natively per locale (concept-vs-product-name policy,
docs/TRANSLATION_RULES.md §1). Keeping them in the fallback told Gemini to keep
ordinary words in English — the opposite of the shipped policy.

Reduced to brand/product/file-format proper nouns only:
API, SDK, Claude, Anthropic, Claude Code, Cowork, Computer Use, SKILL.md, frontmatter.

Low-impact (the fallback only fires for a locale with an empty _protected), but it
removes a policy inconsistency a future contributor/LLM pass could be misled by.
Surfaced by the doc fact-check in #223. 555 unit (constants assertions unchanged) ·
gates green · e2e 20/20.

Author: heznpc

src/lib/constants.js

@@ -14,8 +14,13 @@ const SKILLBRIDGE_MODELS = {
 
 // ==================== DEFAULTS ====================
 
-const DEFAULT_PROTECTED_TERMS =
-  'API, SDK, Claude, Anthropic, Claude Code, Cowork, Dispatch, Computer Use, Subagent, Enterprise, Personal, Plugin, skill, SKILL.md, frontmatter';
+// Gemini "keep-English" fallback, used by getKeepEnglishTerms() only when a locale
+// has no _protected keys. Brand/product/file-format proper nouns ONLY — generic
+// concept words (skill, Subagent, Enterprise, Personal, Plugin, Dispatch) were
+// dropped here to match PR #218, which removed them from the per-locale _protected
+// blocks because they are translated natively per locale (see docs/TRANSLATION_RULES.md
+// §1). Keeping them would tell Gemini to keep ordinary words English.
+const DEFAULT_PROTECTED_TERMS = 'API, SDK, Claude, Anthropic, Claude Code, Cowork, Computer Use, SKILL.md, frontmatter';
 
 // YouTube InnerTube client version — update periodically as needed
 // Source of truth: src/shared/constants.json (keep in sync; validated by scripts/check-bg-sync.js)