refactor(claude): migrate hooks to external scripts and add new hooks

Replace inline command strings in settings.json with external scripts
in .claude/hooks/ for readability and maintainability. Consolidate
three PostToolUse formatters into one script and add markdown/yaml
formatting. Add new hooks: SessionStart context banner, Stop lint
gate, async Bats test runner, idle desktop notification, and
PostToolUseFailure logger.

.claude/hooks/async-bats.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Async Bats runner: run matching test file when a script is edited.
+# Runs in background (async: true) — output appears on next turn.
+
+fp=$(jq -r '.tool_input.file_path // empty')
+[ -z "$fp" ] && exit 0
+
+name=$(basename "$fp")
+test_file="$CLAUDE_PROJECT_DIR/tests/${name}.bats"
+[ ! -f "$test_file" ] && exit 0
+
+echo "Running $test_file ..."
+"$CLAUDE_PROJECT_DIR/node_modules/.bin/bats" "$test_file"

.claude/hooks/log-failures.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# PostToolUseFailure logger: append tool failures to a local log file.
+
+log_file="$CLAUDE_PROJECT_DIR/.claude/hook-failures.log"
+
+entry=$(jq -c '{
+  time: (now | strftime("%Y-%m-%dT%H:%M:%SZ")),
+  tool: .tool_name,
+  error: .error
+}')
+
+echo "$entry" >> "$log_file"
+
+exit 0

.claude/hooks/notify-idle.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Notification hook: alert when Claude goes idle.
+# Uses pushover if available, falls back to macOS native notification.
+
+msg=$(jq -r '.message // "Claude is waiting for input"')
+
+if command -v pushover > /dev/null; then
+  pushover "Claude Code" "$msg"
+elif command -v osascript > /dev/null; then
+  osascript -e "display notification \"$msg\" with title \"Claude Code\""
+fi
+
+exit 0

.claude/hooks/post-edit-format.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Post-edit formatter: auto-format file based on extension.
+# Receives tool output JSON on stdin.
+
+fp=$(jq -r '.tool_input.file_path // empty')
+[ -z "$fp" ] || [ ! -f "$fp" ] && exit 0
+
+case "$fp" in
+  *.sh | */bin/*)
+    head -1 "$fp" | grep -qE '^#!.*(ba)?sh' \
+      && command -v shfmt > /dev/null \
+      && shfmt -i 2 -bn -ci -sr -fn -w "$fp"
+    ;;
+  *.fish)
+    command -v fish_indent > /dev/null && fish_indent -w "$fp"
+    ;;
+  *.lua)
+    command -v stylua > /dev/null && stylua "$fp"
+    ;;
+  *.md)
+    command -v biome > /dev/null && biome format --write "$fp" 2> /dev/null
+    command -v markdown-table-formatter > /dev/null \
+      && markdown-table-formatter "$fp" 2> /dev/null
+    ;;
+  *.yml | *.yaml)
+    command -v prettier > /dev/null && prettier --write "$fp" 2> /dev/null
+    ;;
+esac
+
+exit 0

.claude/hooks/pre-edit-block.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# Pre-edit guard: block vendor/lock files and secrets.d real fish files.
+# Receives tool input JSON on stdin.
+
+fp=$(jq -r '.tool_input.file_path // empty')
+[ -z "$fp" ] && exit 0
+
+case "$fp" in
+  */fzf-tmux | */yarn.lock | */.yarn/*)
+    echo "BLOCKED: $fp is a vendor/lock file — do not edit directly" >&2
+    exit 2
+    ;;
+  */secrets.d/*.fish)
+    case "$(basename "$fp")" in
+      *.example.fish | *.fish.example) exit 0 ;;
+    esac
+    echo "BLOCKED: do not edit $fp directly — it is gitignored." >&2
+    echo "Copy the matching .fish.example file and edit that locally." >&2
+    exit 2
+    ;;
+esac
+
+exit 0

.claude/hooks/session-start-context.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# SessionStart context: print branch, dirty file count, and last commit.
+
+cd "$CLAUDE_PROJECT_DIR" || exit 0
+
+branch=$(git branch --show-current 2> /dev/null)
+dirty=$(git status --short 2> /dev/null | wc -l | tr -d ' ')
+last=$(git log -1 --oneline 2> /dev/null)
+
+echo "=== Dotfiles session context ==="
+echo "Branch : ${branch:-unknown}"
+echo "Dirty  : ${dirty} file(s)"
+echo "Last   : ${last}"
+
+exit 0

.claude/hooks/stop-lint-gate.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# Stop gate: run yarn lint before Claude finishes.
+# Exit 2 sends feedback back and keeps Claude working.
+
+cd "$CLAUDE_PROJECT_DIR" || exit 0
+
+output=$(yarn lint 2>&1)
+status=$?
+
+if [ $status -ne 0 ]; then
+  echo "Lint failed — fix before finishing:" >&2
+  echo "$output" >&2
+  exit 2
+fi
+
+exit 0