Fix invalid YAML frontmatter and consolidate build transformers

Fixes #67: argument-hint values starting with [ were parsed as YAML flow
sequences. Replace structured args arrays in source files with pre-formatted
argument-hint strings, and quote values starting with [ or { in
generateYamlFrontmatter().

Also consolidates 8 nearly-identical transformer files into a single
config-driven createTransformer() factory. Adding a new provider now
requires only a config object in providers.js instead of a full file.

- Replace args source frontmatter with argument-hint strings
- Add YAML quoting for values starting with [ or {
- Add quote stripping to parseFrontmatter() for round-trip support
- Create factory.js + providers.js, delete 8 individual transformers
- Replace 16 explicit build.js calls with a loop over PROVIDERS
- Consolidate 8 test files into 2 (factory + providers)

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

source/skills/adapt/SKILL.md

@@ -1,13 +1,7 @@
 ---
 name: adapt
 description: Adapt designs to work across different screen sizes, devices, contexts, or platforms. Ensures consistent experience across varied environments.
-args:
-  - name: target
-    description: The feature or component to adapt (optional)
-    required: false
-  - name: context
-    description: What to adapt for (mobile, tablet, desktop, print, email, etc.)
-    required: false
+argument-hint: "[target] [context (mobile, tablet, print...)]"
 user-invocable: true
 ---
 

source/skills/animate/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: animate
 description: Review a feature and enhance it with purposeful animations, micro-interactions, and motion effects that improve usability and delight.
-args:
-  - name: target
-    description: The feature or component to animate (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/arrange/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: arrange
 description: Improve layout, spacing, and visual rhythm. Fixes monotonous grids, inconsistent spacing, and weak visual hierarchy to create intentional compositions.
-args:
-  - name: target
-    description: The feature or component to improve layout for (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/audit/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: audit
 description: Perform comprehensive audit of interface quality across accessibility, performance, theming, and responsive design. Generates detailed report of issues with severity ratings and recommendations.
-args:
-  - name: area
-    description: The feature or area to audit (optional)
-    required: false
+argument-hint: "[area (feature, page, component...)]"
 user-invocable: true
 ---
 

source/skills/bolder/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: bolder
 description: Amplify safe or boring designs to make them more visually interesting and stimulating. Increases impact while maintaining usability.
-args:
-  - name: target
-    description: The feature or component to make bolder (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/clarify/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: clarify
 description: Improve unclear UX copy, error messages, microcopy, labels, and instructions. Makes interfaces easier to understand and use.
-args:
-  - name: target
-    description: The feature or component with unclear copy (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/colorize/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: colorize
 description: Add strategic color to features that are too monochromatic or lack visual interest. Makes interfaces more engaging and expressive.
-args:
-  - name: target
-    description: The feature or component to colorize (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/critique/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: critique
 description: Evaluate design effectiveness from a UX perspective. Assesses visual hierarchy, information architecture, emotional resonance, and overall design quality with actionable feedback.
-args:
-  - name: area
-    description: The feature or area to critique (optional)
-    required: false
+argument-hint: "[area (feature, page, component...)]"
 user-invocable: true
 ---
 

source/skills/delight/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: delight
 description: Add moments of joy, personality, and unexpected touches that make interfaces memorable and enjoyable to use. Elevates functional to delightful.
-args:
-  - name: target
-    description: The feature or area to add delight to (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/distill/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: distill
 description: Strip designs to their essence by removing unnecessary complexity. Great design is simple, powerful, and clean.
-args:
-  - name: target
-    description: The feature or component to distill (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/extract/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: extract
 description: Extract and consolidate reusable components, design tokens, and patterns into your design system. Identifies opportunities for systematic reuse and enriches your component library.
-args:
-  - name: target
-    description: The feature, component, or area to extract from (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/harden/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: harden
 description: Improve interface resilience through better error handling, i18n support, text overflow handling, and edge case management. Makes interfaces robust and production-ready.
-args:
-  - name: target
-    description: The feature or area to harden (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/normalize/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: normalize
 description: Normalize design to match your design system and ensure consistency
-args:
-  - name: feature
-    description: The page, route, or feature to normalize (optional)
-    required: false
+argument-hint: "[feature (page, route, component...)]"
 user-invocable: true
 ---
 

source/skills/onboard/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: onboard
 description: Design or improve onboarding flows, empty states, and first-time user experiences. Helps users get started successfully and understand value quickly.
-args:
-  - name: target
-    description: The feature or area needing onboarding (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/optimize/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: optimize
 description: Improve interface performance across loading speed, rendering, animations, images, and bundle size. Makes experiences faster and smoother.
-args:
-  - name: target
-    description: The feature or area to optimize (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/overdrive/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: overdrive
 description: Push interfaces past conventional limits with technically ambitious implementations. Whether that's a shader, a 60fps virtual table, spring physics on a dialog, or scroll-driven reveals — make users ask "how did they do that?"
-args:
-  - name: target
-    description: The feature or area to push into overdrive (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/polish/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: polish
 description: Final quality pass before shipping. Fixes alignment, spacing, consistency, and detail issues that separate good from great.
-args:
-  - name: target
-    description: The feature or area to polish (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/quieter/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: quieter
 description: Tone down overly bold or visually aggressive designs. Reduces intensity while maintaining design quality and impact.
-args:
-  - name: target
-    description: The feature or component to make quieter (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---
 

source/skills/typeset/SKILL.md

@@ -1,10 +1,7 @@
 ---
 name: typeset
 description: Improve typography by fixing font choices, hierarchy, sizing, weight consistency, and readability. Makes text feel intentional and polished.
-args:
-  - name: target
-    description: The feature or component to improve typography for (optional)
-    required: false
+argument-hint: "[target]"
 user-invocable: true
 ---