Migrate from Claude Code to OpenCode structure

- Move legacy content to legacy/ folder (old, old2, docs, learnings, scripts)
- Create new .opencode/ structure with skills/, tools/, agents/ folders
- Update Makefile to symlink to ~/.config/opencode/ instead of ~/.claude/
- Update Makefile to manage skills, tools, and agents (remove settings.json)
- Simplify install/uninstall (no backup logic)
- Add README.md documenting the new structure
- Keep settings.json as historical reference

legacy/scripts/pre-commit-checks.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+# Pre-commit validation script for Claude Code
+# Validates YAML, checks for secrets, validates K8s manifests
+
+set -e
+
+# Get staged files
+STAGED_FILES=$(git diff --cached --name-only 2>/dev/null || echo "")
+
+if [ -z "$STAGED_FILES" ]; then
+  exit 0
+fi
+
+# Check for potential secrets in staged files
+echo "Checking for potential secrets..."
+SECRET_PATTERN='(password|secret|token|api_key|apikey|private_key).*[=:].{20,}'
+if echo "$STAGED_FILES" | xargs grep -l -iE "$SECRET_PATTERN" 2>/dev/null | grep -v '.sops.yaml' | grep -v 'secret.*\.enc\.yaml'; then
+  echo "WARNING: Potential secrets detected in staged files (excluding SOPS-encrypted files)"
+  echo "Please verify these are encrypted or not actual secrets."
+fi
+
+# Validate YAML syntax
+echo "Validating YAML syntax..."
+for file in $(echo "$STAGED_FILES" | grep -E '\.ya?ml$'); do
+  if [ -f "$file" ]; then
+    if ! python3 -c "import yaml; yaml.safe_load(open('$file'))" 2>/dev/null; then
+      echo "ERROR: Invalid YAML syntax: $file"
+      exit 1
+    fi
+  fi
+done
+
+# Validate Kubernetes manifests (if kubectl available)
+if command -v kubectl &>/dev/null; then
+  echo "Validating Kubernetes manifests..."
+  for file in $(echo "$STAGED_FILES" | grep -E '\.ya?ml$'); do
+    if [ -f "$file" ] && grep -q "^kind:" "$file" 2>/dev/null; then
+      # Skip SOPS-encrypted files and kustomization files
+      if echo "$file" | grep -qE '(\.sops\.yaml|\.enc\.yaml|kustomization\.yaml)$'; then
+        continue
+      fi
+      if ! kubectl apply --dry-run=client -f "$file" 2>/dev/null; then
+        echo "WARNING: Kubernetes validation failed: $file (may be expected for partial manifests)"
+      fi
+    fi
+  done
+fi
+
+echo "Pre-commit checks passed."
+exit 0