feat: Add digital, dry, ink, and paint brush presets; implement regression testing hooks

- Introduced new crates for digital brushes, dry media brushes, ink brushes, and paint brushes, each containing various presets.
- Updated the menus to include "Paste Special" and "Paste as New Layer" options.
- Enhanced the feature scorecard tests to validate selection texture encoding.
- Added a regression gate workflow for automated testing on push and pull requests.
- Implemented Git hooks for pre-commit checks to ensure code formatting and run tests before commits.
- Created a settings file for local configurations.

.githooks/pre-commit

@@ -1,21 +1,16 @@
-#!/bin/bash
+#!/usr/bin/env bash
+set -Eeuo pipefail
 
-CHANGED_FILES=$(git diff --cached --name-only)
-if [ -z "$CHANGED_FILES" ]; then
-    exit 0
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+cd "$REPO_ROOT"
+
+echo "Running mandatory staged-change regression gate..."
+"$REPO_ROOT/scripts/precommit-test-gate.sh"
+
+CHANGED_FILES="$(git diff --cached --name-only --diff-filter=ACMRDTUXB)"
+if [[ -n "$CHANGED_FILES" ]]; then
+    echo "Running semantic impact analysis..."
+    python3 "$REPO_ROOT/.githooks/semantic_analyzer.py" "$CHANGED_FILES"
 fi
 
-echo "🔍 Semantik etki analizi başlatılıyor..."
-echo "Değişen dosyalar:"
-echo "$CHANGED_FILES"
-echo "--------------------------------------------------"
-
-python3 .githooks/semantic_analyzer.py "$CHANGED_FILES"
-ANALYSIS_RESULT=$?
-
-if [ $ANALYSIS_RESULT -ne 0 ]; then
-    echo "❌ COMMIT ENGELLENDİ: Kritik bir modül risk altında veya testler başarısız."
-    exit 1
-fi
-
-exit 0
+echo "Pre-commit checks passed."