feat: expand lint hook to git push, add /lint skill

- Change PreToolUse lint hook from gh pr create to git push
- Add /lint skill for manual linting (available to Claude and user)
- Add linting guidance to CLAUDE.md (fix issues, disable directives as last resort)

Co-Authored-By: Claude <claude@anthropic.com>

.claude/hooks/pre-pr-lint.sh

@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 #
-# PreToolUse hook: Run shellcheck and actionlint before PR creation
+# PreToolUse hook: Run shellcheck and actionlint before git push
 #
 # Checks shell scripts and GitHub Actions workflows for issues
-# before allowing gh pr create to proceed.
+# before allowing git push to proceed.
 
 set -o pipefail
 
@@ -19,8 +19,8 @@ if [[ "$tool_name" != 'Bash' ]]; then
 	exit 0
 fi
 
-# Only process gh pr create commands
-if [[ "$command" != *'gh pr create'* ]]; then
+# Only process git push commands
+if [[ "$command" != *'git push'* ]]; then
 	exit 0
 fi
 
@@ -77,9 +77,9 @@ if [[ -n "$changed_workflows" ]]; then
 	check_actionlint "$changed_workflows"
 fi
 
-# If errors found, block the PR creation
+# If errors found, block the push
 if [[ -n "$errors" ]]; then
-	printf '%s\n' 'Lint checks failed. Fix these issues before creating the PR:' >&2
+	printf '%s\n' 'Lint checks failed. Fix these issues before pushing:' >&2
 	printf '\n%s' "$errors" >&2
 	exit 2
 fi

.claude/skills/lint/SKILL.md

@@ -0,0 +1,53 @@
+---
+name: lint
+description: Run shellcheck and actionlint on shell scripts and GitHub Actions workflows. Use before pushing or when fixing lint issues.
+---
+
+Run linting tools on shell scripts and GitHub Actions workflows in this project.
+
+## Your Task
+
+Run the following checks on changed files (relative to main branch):
+
+### 1. Shell Scripts (shellcheck)
+
+```bash
+# Find changed shell scripts
+changed_scripts=$(git diff --name-only main...HEAD 2>/dev/null | grep -E '\.sh$')
+
+# Run shellcheck on each
+for script in $changed_scripts; do
+    if [[ -f "$script" ]]; then
+        shellcheck -f gcc "$script"
+    fi
+done
+```
+
+### 2. GitHub Actions Workflows (actionlint)
+
+```bash
+# Find changed workflow files
+changed_workflows=$(git diff --name-only main...HEAD 2>/dev/null | grep -E '\.github/workflows/.*\.ya?ml$')
+
+# Run actionlint on each
+for workflow in $changed_workflows; do
+    if [[ -f "$workflow" ]]; then
+        actionlint "$workflow"
+    fi
+done
+```
+
+## Handling Issues
+
+When lint issues are found:
+
+1. **Fix the issues** - Correct the code to resolve warnings/errors
+2. **Only use disable directives as a last resort** - If a warning is a false positive or truly unavoidable, add a disable comment with explanation:
+   ```bash
+   # shellcheck disable=SC2034  # Variable used by sourcing script
+   ```
+3. **Report what was fixed** - Summarize the changes made
+
+## Optional Guidance
+
+$ARGUMENTS

CLAUDE.md

@@ -14,6 +14,17 @@ All shell scripts in this project must follow the [Bash Style Guide](STYLEGUIDE.
 - Lowercase variables; UPPERCASE only for constants/exports
 - Use `local` in functions, avoid `set -e` and `eval`
 
+### Linting
+
+Shell scripts are checked with `shellcheck` and GitHub Actions workflows with `actionlint` before pushing. When lint issues are found:
+
+1. **Fix the code** - Correct the underlying issue rather than suppressing the warning
+2. **Disable directives are a last resort** - Only use `# shellcheck disable=SCXXXX` when:
+   - The warning is a false positive
+   - The pattern is intentional and unavoidable
+   - Always add a comment explaining why the disable is needed
+3. **Run `/lint` to check manually** - Use this skill to check for issues before pushing
+
 ## GitHub Workflow
 
 ### General Approach