chore(skill-author): backfill sources provenance from agentskillsio research

Records the upstream agentskills.io sources that informed skill-author,
completing the research → docs → skill provenance chain introduced in
the previous commit.

- New references/sources.md with all 7 extracted agentskillsio sources,
  Contributing files attributed per-source to SKILL.md, references/deployment-modes.md,
  and references/scripts.md
- source_keys frontmatter added to SKILL.md (all 7 slugs), references/deployment-modes.md
  (agentskills-spec), and references/scripts.md (agentskills-using-scripts)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/kyberforge/skills/skill-author/README.md

@@ -36,6 +36,7 @@ If the destination is inside a plugin directory, read `references/deployment-mod
 | `scripts/new-skill.sh` | Copies annotated templates to the destination to scaffold a new skill |
 | `references/deployment-modes.md` | Plugin vs standalone differences and cache isolation rules (loaded on demand) |
 | `references/scripts.md` | Package runners, inline dependency patterns, and full script contract (loaded on demand) |
+| `references/sources.md` | Upstream research sources and which skill files each contributed to |
 | `assets/templates/SKILL.md` | Annotated SKILL.md template |
 | `assets/templates/README.md` | Annotated README template for the new skill |
 | `assets/templates/scripts/README.md` | Placeholder for bundled scripts |

plugins/kyberforge/skills/skill-author/SKILL.md

@@ -13,6 +13,14 @@ description: >
 allowed-tools: Bash Read Write Edit
 metadata:
   category: factory
+  source_keys:
+    - agentskills-home
+    - agentskills-spec
+    - agentskills-best-practices
+    - agentskills-optimizing-descriptions
+    - agentskills-evaluating-skills
+    - agentskills-using-scripts
+    - agentskills-quickstart
 ---
 
 ## Gotchas

plugins/kyberforge/skills/skill-author/references/deployment-modes.md

@@ -1,3 +1,8 @@
+---
+source_keys:
+  - agentskills-spec
+---
+
 # Deployment Modes
 
 Skills deploy in two modes. Both resolve relative paths from the skill root — the SKILL.md body works the same in either. Differences only arise when referencing files *outside* the skill directory.

plugins/kyberforge/skills/skill-author/references/scripts.md

@@ -1,3 +1,8 @@
+---
+source_keys:
+  - agentskills-using-scripts
+---
+
 # Scripts Reference
 
 ## Package runners (no install required)

plugins/kyberforge/skills/skill-author/references/sources.md

@@ -0,0 +1,57 @@
+# Sources
+
+## agentskills-home
+
+- **URL:** https://agentskills.io/home.md
+- **Description:** Agent Skills overview — what it is, why it exists, progressive disclosure model, ecosystem of 35+ implementing tools
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## agentskills-spec
+
+- **URL:** https://agentskills.io/specification.md
+- **Description:** Complete SKILL.md format specification — frontmatter fields, constraints, body content, optional directories, progressive disclosure levels, file references, validation
+- **Contributing files:** SKILL.md, references/deployment-modes.md
+- **Status:** `extracted`
+
+## agentskills-best-practices
+
+- **URL:** https://agentskills.io/skill-creation/best-practices.md
+- **Description:** Best practices for skill creators — starting from real expertise, spending context wisely, calibrating control, instruction patterns (gotchas, templates, checklists, validation loops)
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## agentskills-optimizing-descriptions
+
+- **URL:** https://agentskills.io/skill-creation/optimizing-descriptions.md
+- **Description:** How to systematically test and improve skill descriptions for triggering accuracy — eval queries, trigger rate testing, train/validation splits, optimization loop
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## agentskills-evaluating-skills
+
+- **URL:** https://agentskills.io/skill-creation/evaluating-skills.md
+- **Description:** Eval-driven skill quality improvement — test case design, workspace structure, assertion writing, grading, benchmarking, human review, iteration loop
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## agentskills-using-scripts
+
+- **URL:** https://agentskills.io/skill-creation/using-scripts.md
+- **Description:** Using scripts in skills — one-off commands, self-contained scripts with inline dependencies, designing scripts for agentic use (no interactive prompts, --help, structured output, idempotency)
+- **Contributing files:** SKILL.md, references/scripts.md
+- **Status:** `extracted`
+
+## agentskills-quickstart
+
+- **URL:** https://agentskills.io/skill-creation/quickstart.md
+- **Description:** Step-by-step guide to creating a first skill (roll-dice example), how discovery/activation/execution work in practice
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## agentskills-llms-txt
+
+- **URL:** https://agentskills.io/llms.txt
+- **Description:** Documentation index used for source discovery — lists all available pages with URLs
+- **Contributing files:** (none — used for discovery only)
+- **Status:** `extracted`