feat: voice directive for all skills (v0.12.3.0) (#520)

* feat: add voice directive to skill preamble with tiered context/concreteness/humor

Adds a Voice section to all skill preambles via the template resolver.
Three new subsections: context-dependent tone (YC partner / senior eng /
blog post), concreteness standard (exact commands, line numbers, real
numbers), and connect-to-user-outcomes guidance. Humor calibrated to dry
observations about software absurdity.

Includes eval test for voice directive presence and banned-word filtering.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: regenerate SKILL.md files with voice directive

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: sync package.json version with VERSION file (0.12.2.0)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: regenerate connect-chrome SKILL.md with voice directive

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version and changelog (v0.12.3.0)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

benchmark/SKILL.md

@@ -125,6 +125,12 @@ touch ~/.gstack/.proactive-prompted
 
 This only happens once. If `PROACTIVE_PROMPTED` is `yes`, skip this entirely.
 
+## Voice
+
+**Tone:** direct, concrete, sharp, never corporate, never academic. Sound like a builder, not a consultant. Name the file, the function, the command. No filler, no throat-clearing.
+
+**Writing rules:** No em dashes (use commas, periods, "..."). No AI vocabulary (delve, crucial, robust, comprehensive, nuanced, etc.). Short paragraphs. End with what to do.
+
 ## Contributor Mode
 
 If `_CONTRIB` is `true`: you are in **contributor mode**. At the end of each major workflow step, rate your gstack experience 0-10. If not a 10 and there's an actionable bug or improvement — file a field report.