chore(skills): add version/author/tags frontmatter to all 60 skills (#86)

The `librefang` dashboard's federated catalog UI surfaces every
optional SKILL.md frontmatter field — version, author, and tags — but
the existing skills only carry `name` + `description`, so the catalog
cards render visually empty:

  ┌────────────────┐
  │ ansible        │  ← no version, no author, no tags shown
  │ FangHub        │
  │ Ansible auto…  │
  └────────────────┘

Populate the three optional fields across every skill so the catalog
fills out as designed:

  ┌─────────────────────┐
  │ ansible             │
  │ skill · librefang   │
  │ · v0.1.0            │
  │ Ansible auto…       │
  │ [devops][automation]│
  │ [infra]             │
  └─────────────────────┘

Choices
- author = `librefang`. Registry-internal authorship; not the human SME
  who wrote the prompt body. Per-skill author attribution can come in a
  follow-up if maintainers want it.
- version = `0.1.0` baseline. Future content updates bump per-skill.
- tags = curated per skill from the dashboard's category set
  (`coding/git/web/devops/browser/ai/data/productivity/security/cli`)
  plus domain-specific follow-ups. First tag is the primary category.

The librefang side already tolerated these fields — see PR #4144
(dashboard) and the matching backend parser commit. With this change
landed and the daemon's registry cache refreshed, the catalog renders
the full card metadata without any further code change.

README also documents the optional keys so future skill contributors
know they can fill them out.

skills/README.md

@@ -25,13 +25,28 @@ skills/
 ---
 name: rust-expert
 description: "Rust programming expert for ownership, lifetimes, async/await, traits, and unsafe code"
+version: 0.1.0
+author: librefang
+tags: [coding, language]
 ---
 # Rust Programming Expertise
 
 You are an expert Rust developer with deep understanding of the ownership system...
 ```
 
-The frontmatter must contain `name` and `description`. The Markdown body becomes the injected prompt.
+The frontmatter must contain `name` and `description`. The other keys are
+optional and the registry parser tolerates their absence:
+
+- `version` (default `null`) — semver string. Bump per content update.
+- `author`  (default `null`) — owner of the prompt body. Use `librefang`
+  for first-party skills under this registry.
+- `tags`    (default `[]`)  — inline YAML list. The dashboard's catalog
+  surfaces these as filter chips and as visible tags on each skill
+  card. Standard buckets: `coding`, `git`, `web`, `devops`, `browser`,
+  `ai`, `data`, `productivity`, `security`, `cli`. Add domain-specific
+  follow-ups freely (e.g. `[devops, kubernetes, k8s]`).
+
+The Markdown body after the closing `---` becomes the injected prompt.
 
 ### skill.toml format (optional)
 
@@ -188,7 +203,7 @@ librefang skill test ./skills/meeting-agenda \
 
 ## Adding a New Skill
 
-1. Create `skills/<name>/SKILL.md` with frontmatter (`name`, `description`) and the prompt body.
+1. Create `skills/<name>/SKILL.md` with frontmatter (`name`, `description`, plus optional `version`, `author`, `tags`) and the prompt body.
 2. If you need `[runtime]`, `[input]`, or structured metadata, add `skills/<name>/skill.toml`.
 3. Add implementation files (`main.py`, etc.) when `runtime` is not `promptonly`.
 4. Run `python scripts/validate.py`.