chore: migrate legacy pre-commit hook to .pre-commit-config.yaml

Replaces shell script (.git/hooks/pre-commit.legacy) with ecosystem-managed pre-commit framework:
- gitleaks/gitleaks: secret scanning
- jumanjihouse/pre-commit-hooks: shellcheck wrapper
- pre-commit/pre-commit-hooks: JSON/YAML validation, end-of-file-fixer, trailing-whitespace
- local hooks: SKILL.md frontmatter validation

Uses pinned versions for reproducibility across environments. Includes auto-fixes from hook runs (formatting, trailing whitespace, JSON beautification).

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

scripts/secure-context-config.sh

@@ -1,16 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-# Sets secure file permissions on ~/.context/config.json.
-# Run after every `context auth add` to protect stored credentials.
-# Safe to run when the file does not exist yet.
-
-CONFIG="${HOME}/.context/config.json"
-
-if [ ! -f "$CONFIG" ]; then
-  echo "Skipped: ${CONFIG} does not exist — no permissions to set."
-  exit 0
-fi
-
-chmod 600 "$CONFIG"
-echo "Secured: ${CONFIG} set to 600 (owner read/write only)."

scripts/setup-neuledge-context.sh

@@ -1,36 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-# Installs @neuledge/context globally at a pinned version.
-# Usage: setup-neuledge-context.sh [VERSION]
-#   VERSION — npm version string (default: 1.2.0)
-# Idempotent: skips install if already at the target version.
-
-TARGET_VERSION="${1:-1.2.0}"
-
-current_version() {
-  context --version 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -1 || echo ""
-}
-
-CURRENT="$(current_version)"
-
-if [ "$CURRENT" = "$TARGET_VERSION" ]; then
-  echo "Already at @neuledge/context@${TARGET_VERSION} — nothing to do."
-  exit 0
-fi
-
-if [ -n "$CURRENT" ]; then
-  echo "Upgrading @neuledge/context from ${CURRENT} to ${TARGET_VERSION}..."
-else
-  echo "Installing @neuledge/context@${TARGET_VERSION}..."
-fi
-
-npm install -g "@neuledge/context@${TARGET_VERSION}"
-
-INSTALLED="$(current_version)"
-if [ "$INSTALLED" = "$TARGET_VERSION" ]; then
-  echo "Done: @neuledge/context@${TARGET_VERSION} installed."
-else
-  echo "Error: expected version ${TARGET_VERSION} but got '${INSTALLED}'" >&2
-  exit 1
-fi