feat(kyberforge): add pc-author and pc-run pre-commit skills

## Why
Pre-commit config management was entirely manual — no skill existed to
help create, modify, or validate `.pre-commit-config.yaml`, or to run,
install, and maintain the pre-commit setup. These two skills close that
gap with clear scope separation: authoring vs. execution.

## Implementation Notes
- `pc-author` owns `.pre-commit-config.yaml` only (no hook publishing,
  no install). Runs `pre-commit validate-config` after every write.
  Shallow file-extension scan drives proactive hook recommendations;
  rev staleness is flagged against `references/hooks-by-language.md`
  rather than hardcoded versions. Remove path reverts on failure.
- `pc-run` owns install, run, autoupdate, gc, and clean. Defaults to
  `--all-files`. Install warns about existing `.git/hooks/` files being
  overwritten by `-f`. Clean requires HITL confirmation. Failure
  interpretation delegates to `references/failure-patterns.md`.
- Provenance wired to `plugins/kyberforge/docs/research/docs/pre-commit/`.
- Both skills resolve via the existing `"skills/"` glob in `plugin.json`.

## Impact
Two new slash commands available after `claude plugin install kyberforge@holocron`:
`/pc-author` and `/pc-run`.

Refs: #12

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P87CiC58Ru2PPWYTeXtjHT

plugins/kyberforge/skills/pc-author/references/hooks-by-language.md

@@ -0,0 +1,104 @@
+---
+source_keys:
+  - context7-pre-commit-com
+  - pre-commit-com
+  - context7-pre-commit-hooks
+  - pre-commit-hooks-github
+---
+
+# Hook Recommendations by Language / Context
+
+Use this table when creating a config from scratch or recommending hooks to add.
+Always check the existing config for duplicates before proposing.
+
+## Universal (recommend for every repo)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `end-of-file-fixer` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Ensures files end with a newline — prevents spurious diffs |
+| `trailing-whitespace` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Strips trailing whitespace — prevents invisible diff noise |
+| `check-merge-conflict` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Catches unresolved merge markers before commit |
+| `detect-private-key` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Blocks PEM private key material |
+
+## Shell (`.sh`)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `shellcheck` | `https://github.com/jumanjihouse/pre-commit-hooks` | `3.0.0` | Static analysis for shell scripts; catches common errors |
+
+Recommended args: `args: [--severity=warning]`
+
+## Python (`.py`)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `check-ast` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Validates Python files parse as valid AST |
+| `check-builtin-literals` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Enforces literal syntax for `dict()`, `list()` |
+
+For formatting: check if `black`, `ruff`, or `isort` is already configured in `pyproject.toml` before recommending them.
+
+## JSON (`.json`)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `check-json` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Validates JSON parses correctly |
+| `pretty-format-json` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Auto-formats JSON (fixer — warns user to re-stage after commit) |
+
+## YAML (`.yaml`, `.yml`)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `check-yaml` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Validates YAML parses correctly |
+
+For Kubernetes/Helm YAML with custom tags, add `args: ['--unsafe']` and `exclude: ^helm/templates/`.
+
+## TOML (`.toml`)
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `check-toml` | `https://github.com/pre-commit/pre-commit-hooks` | `v6.0.0` | Validates TOML parses correctly |
+
+## Secrets / security
+
+| Hook ID | Repo | Rev | Rationale |
+|---------|------|-----|-----------|
+| `gitleaks` | `https://github.com/gitleaks/gitleaks` | `v8.21.2` | Scans for secrets and high-entropy strings |
+
+## Commit message
+
+| Hook ID | Repo | Rev | Stage | Rationale |
+|---------|------|-----|-------|-----------|
+| `conventional-pre-commit` | `https://github.com/compilerla/conventional-pre-commit` | `v2.4.0` | `commit-msg` | Enforces Conventional Commits format |
+
+When adding commit-msg hooks, also add `default_install_hook_types: [pre-commit, commit-msg]` to the top-level config if not already present.
+
+## Meta-validation (add last, after all other repos)
+
+```yaml
+- repo: meta
+  hooks:
+    - id: check-hooks-apply       # catches hooks that match no files
+    - id: check-useless-excludes  # catches exclude patterns that match no files
+```
+
+## Local hooks (repo: local)
+
+Use for repo-specific scripts that don't belong in an external hook repo.
+
+```yaml
+- repo: local
+  hooks:
+    - id: run-tests
+      name: Run test suite
+      entry: bash tests/run-tests.sh
+      language: unsupported_script
+      pass_filenames: false
+      always_run: true
+      stages: [pre-push]
+```
+
+Language choices for local hooks:
+- `unsupported` — system PATH tool (pre-commit does not manage env)
+- `unsupported_script` — script at a repo-relative path
+- `fail` — always-fail guard; `entry` text becomes the error message
+- `python` — isolated venv; use `additional_dependencies` for pip packages

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

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+# Sources
+
+## context7-pre-commit-com
+
+- **URL:** context7:/pre-commit/pre-commit.com
+- **Description:** Official pre-commit.com documentation — installation, configuration schema, CLI reference, hook authoring, advanced features, troubleshooting
+- **Contributing files:** SKILL.md, references/hooks-by-language.md
+- **Research doc:** plugins/kyberforge/docs/research/docs/pre-commit/sources.md
+- **Status:** `extracted`
+
+## pre-commit-com
+
+- **URL:** https://pre-commit.com/
+- **Description:** Pre-commit framework homepage — full docs covering install, config, CLI, hook authoring, stages, local hooks, meta hooks, hazmat helpers, CI integration
+- **Contributing files:** SKILL.md, references/hooks-by-language.md
+- **Research doc:** plugins/kyberforge/docs/research/docs/pre-commit/sources.md
+- **Status:** `extracted`
+
+## context7-pre-commit-hooks
+
+- **URL:** context7:/pre-commit/pre-commit-hooks
+- **Description:** Official pre-commit-hooks collection — all available hook IDs with options and examples
+- **Contributing files:** references/hooks-by-language.md
+- **Research doc:** plugins/kyberforge/docs/research/docs/pre-commit/sources.md
+- **Status:** `extracted`
+
+## pre-commit-hooks-github
+
+- **URL:** https://raw.githubusercontent.com/pre-commit/pre-commit-hooks/main/README.md
+- **Description:** Official pre-commit-hooks README — complete hook listing with all args, categories, deprecated hooks, and latest version (v6.0.0)
+- **Contributing files:** references/hooks-by-language.md
+- **Research doc:** plugins/kyberforge/docs/research/docs/pre-commit/sources.md
+- **Status:** `extracted`