feat: 新增前端认证UI组件

- 新增auth/认证相关UI组件

app-android/app/src/main/java/com/huaga/life_echo/ui/components/auth/PasswordStrengthIndicator.kt

@@ -0,0 +1,170 @@
+package com.huaga.life_echo.ui.components.auth
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * 密码强度等级
+ */
+enum class PasswordStrength(val label: String, val color: Color) {
+    WEAK("弱", Color(0xFFEF5350)),
+    MEDIUM("中", Color(0xFFFF9800)),
+    STRONG("强", Color(0xFF66BB6A))
+}
+
+/**
+ * 计算密码强度
+ */
+fun calculatePasswordStrength(password: String): PasswordStrength? {
+    if (password.isEmpty()) return null
+    
+    var score = 0
+    
+    // 长度评分
+    when {
+        password.length >= 12 -> score += 3
+        password.length >= 8 -> score += 2
+        password.length >= 6 -> score += 1
+    }
+    
+    // 包含小写字母
+    if (password.any { it.isLowerCase() }) score += 1
+    
+    // 包含大写字母
+    if (password.any { it.isUpperCase() }) score += 1
+    
+    // 包含数字
+    if (password.any { it.isDigit() }) score += 1
+    
+    // 包含特殊字符
+    if (password.any { !it.isLetterOrDigit() }) score += 1
+    
+    return when {
+        score >= 6 -> PasswordStrength.STRONG
+        score >= 4 -> PasswordStrength.MEDIUM
+        else -> PasswordStrength.WEAK
+    }
+}
+
+/**
+ * 密码强度指示器组件
+ * 
+ * @param password 当前密码
+ */
+@Composable
+fun PasswordStrengthIndicator(
+    password: String,
+    modifier: Modifier = Modifier
+) {
+    val strength = remember(password) { calculatePasswordStrength(password) }
+    
+    if (strength != null) {
+        Row(
+            modifier = modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            // 强度条
+            Row(
+                modifier = Modifier.weight(1f),
+                horizontalArrangement = Arrangement.spacedBy(4.dp)
+            ) {
+                repeat(3) { index ->
+                    Box(
+                        modifier = Modifier
+                            .weight(1f)
+                            .height(4.dp)
+                            .background(
+                                color = when {
+                                    index == 0 -> strength.color
+                                    index == 1 && strength != PasswordStrength.WEAK -> strength.color
+                                    index == 2 && strength == PasswordStrength.STRONG -> strength.color
+                                    else -> MaterialTheme.colorScheme.surfaceVariant
+                                },
+                                shape = RoundedCornerShape(2.dp)
+                            )
+                    )
+                }
+            }
+            
+            // 强度文字
+            Text(
+                text = "强度：${strength.label}",
+                fontSize = 12.sp,
+                color = strength.color
+            )
+        }
+    }
+}
+
+/**
+ * 密码要求提示组件
+ */
+@Composable
+fun PasswordRequirements(
+    password: String,
+    modifier: Modifier = Modifier
+) {
+    Column(
+        modifier = modifier.fillMaxWidth(),
+        verticalArrangement = Arrangement.spacedBy(4.dp)
+    ) {
+        Text(
+            text = "密码要求：",
+            fontSize = 12.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        
+        PasswordRequirementItem(
+            text = "至少6个字符",
+            met = password.length >= 6
+        )
+        
+        PasswordRequirementItem(
+            text = "建议包含大小写字母、数字和特殊字符",
+            met = password.any { it.isLowerCase() } &&
+                  password.any { it.isUpperCase() } &&
+                  password.any { it.isDigit() }
+        )
+    }
+}
+
+@Composable
+private fun PasswordRequirementItem(
+    text: String,
+    met: Boolean
+) {
+    Row(
+        horizontalArrangement = Arrangement.spacedBy(4.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = if (met) "✓" else "○",
+            fontSize = 12.sp,
+            color = if (met) {
+                Color(0xFF66BB6A)
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            }
+        )
+        
+        Text(
+            text = text,
+            fontSize = 12.sp,
+            color = if (met) {
+                Color(0xFF66BB6A)
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            }
+        )
+    }
+}

app-android/app/src/main/java/com/huaga/life_echo/ui/components/auth/SendSmsButton.kt

@@ -0,0 +1,87 @@
+package com.huaga.life_echo.ui.components.auth
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * 发送短信验证码按钮组件
+ * 
+ * @param countdown 倒计时秒数，0表示可以发送
+ * @param enabled 是否启用按钮
+ * @param onClick 点击回调
+ */
+@Composable
+fun SendSmsButton(
+    countdown: Int,
+    enabled: Boolean = true,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val canSend = countdown == 0 && enabled
+    
+    Button(
+        onClick = onClick,
+        enabled = canSend,
+        modifier = modifier.height(56.dp),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (canSend) {
+                MaterialTheme.colorScheme.primary
+            } else {
+                MaterialTheme.colorScheme.surfaceVariant
+            },
+            contentColor = if (canSend) {
+                MaterialTheme.colorScheme.onPrimary
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            }
+        )
+    ) {
+        Text(
+            text = if (countdown > 0) {
+                "${countdown}秒后重发"
+            } else {
+                "发送验证码"
+            },
+            fontSize = 14.sp
+        )
+    }
+}
+
+/**
+ * 紧凑版发送短信验证码按钮（用于输入框右侧）
+ */
+@Composable
+fun CompactSendSmsButton(
+    countdown: Int,
+    enabled: Boolean = true,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val canSend = countdown == 0 && enabled
+    
+    TextButton(
+        onClick = onClick,
+        enabled = canSend,
+        modifier = modifier,
+        colors = ButtonDefaults.textButtonColors(
+            contentColor = if (canSend) {
+                MaterialTheme.colorScheme.primary
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            }
+        )
+    ) {
+        Text(
+            text = if (countdown > 0) {
+                "${countdown}s"
+            } else {
+                "获取验证码"
+            },
+            fontSize = 14.sp
+        )
+    }
+}

app-android/app/src/main/java/com/huaga/life_echo/ui/components/auth/SmsCodeInput.kt

@@ -0,0 +1,96 @@
+package com.huaga.life_echo.ui.components.auth
+
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * 短信验证码输入框组件
+ * 
+ * @param code 当前输入的验证码
+ * @param onCodeChange 验证码变化回调
+ * @param codeLength 验证码长度，默认6位
+ * @param enabled 是否启用输入
+ */
+@Composable
+fun SmsCodeInput(
+    code: String,
+    onCodeChange: (String) -> Unit,
+    codeLength: Int = 6,
+    enabled: Boolean = true,
+    modifier: Modifier = Modifier
+) {
+    BasicTextField(
+        value = code,
+        onValueChange = { newValue ->
+            // 只允许输入数字，且不超过指定长度
+            if (newValue.length <= codeLength && newValue.all { it.isDigit() }) {
+                onCodeChange(newValue)
+            }
+        },
+        enabled = enabled,
+        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+        textStyle = TextStyle(
+            fontSize = 20.sp,
+            fontWeight = FontWeight.Bold,
+            textAlign = TextAlign.Center,
+            color = MaterialTheme.colorScheme.onSurface
+        ),
+        modifier = modifier,
+        decorationBox = { innerTextField ->
+            Row(
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                repeat(codeLength) { index ->
+                    Box(
+                        modifier = Modifier
+                            .size(48.dp)
+                            .border(
+                                width = 2.dp,
+                                color = when {
+                                    !enabled -> MaterialTheme.colorScheme.outline.copy(alpha = 0.3f)
+                                    index == code.length -> MaterialTheme.colorScheme.primary
+                                    index < code.length -> MaterialTheme.colorScheme.primary.copy(alpha = 0.5f)
+                                    else -> MaterialTheme.colorScheme.outline
+                                },
+                                shape = RoundedCornerShape(12.dp)
+                            ),
+                        contentAlignment = Alignment.Center
+                    ) {
+                        Text(
+                            text = if (index < code.length) code[index].toString() else "",
+                            style = TextStyle(
+                                fontSize = 24.sp,
+                                fontWeight = FontWeight.Bold,
+                                color = if (enabled) {
+                                    MaterialTheme.colorScheme.onSurface
+                                } else {
+                                    MaterialTheme.colorScheme.onSurface.copy(alpha = 0.3f)
+                                }
+                            )
+                        )
+                    }
+                }
+            }
+            // 隐藏原始输入框
+            Box(modifier = Modifier.size(0.dp)) {
+                innerTextField()
+            }
+        }
+    )
+}