feat: Add template system to weevil new command

Implements template-based project creation allowing teams to start with
professional example code instead of empty projects.

Features:
- Two templates: 'basic' (minimal) and 'testing' (45-test showcase)
- Template variable substitution ({{PROJECT_NAME}}, etc.)
- Template validation with helpful error messages
- `weevil new --list-templates` command
- Template files embedded in binary at compile time

Technical details:
- Templates stored in templates/basic/ and templates/testing/
- Files ending in .template have variables replaced
- Uses include_dir! macro to embed templates in binary
- Returns file count for user feedback

Testing template includes:
- 3 complete subsystems (MotorCycler, WallApproach, TurnController)
- Hardware abstraction layer with mock implementations
- 45 comprehensive tests (unit, integration, system)
- Professional documentation (DESIGN_AND_TEST_PLAN.md, etc.)

Usage:
  weevil new my-robot                    # basic template
  weevil new my-robot --template testing # testing showcase
  weevil new --list-templates            # show available templates

This enables FTC teams to learn from working code and best practices
rather than starting from scratch.

templates/basic/build.gradle.template

@@ -0,0 +1,58 @@
+plugins {
+    id 'com.android.application'
+}
+
+android {
+    namespace 'org.firstinspires.ftc.{{PACKAGE_NAME}}'
+    compileSdk 34
+
+    defaultConfig {
+        applicationId 'org.firstinspires.ftc.{{PACKAGE_NAME}}'
+        minSdk 24
+        targetSdk 34
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    sourceSets {
+        main {
+            java {
+                srcDirs = ['src/main/java']
+            }
+        }
+        test {
+            java {
+                srcDirs = ['src/test/java']
+            }
+        }
+    }
+}
+
+repositories {
+    mavenCentral()
+    google()
+}
+
+dependencies {
+    implementation 'org.firstinspires.ftc:RobotCore:10.1.1'
+    implementation 'org.firstinspires.ftc:Hardware:10.1.1'
+    implementation 'org.firstinspires.ftc:FtcCommon:10.1.1'
+    implementation 'androidx.appcompat:appcompat:1.6.1'
+
+    testImplementation 'junit:junit:4.13.2'
+    testImplementation 'org.mockito:mockito-core:5.3.1'
+}