Add Luxsin curve API client and validation functionality

- Introduced a new module `curve_client.py` for interacting with the Luxsin curve API, including functions for custom Base64 decoding and parametric EQ validation.
- Implemented error handling for API responses and validation checks for curve data.
- Removed outdated test files to streamline the codebase.
- Updated brand creation and update logic in `brands.py` to ensure brand names are validated and checked for duplicates.
- Enhanced model handling in `models.py` with new validation and push-to-search functionality, integrating curve validation before pushing to Meilisearch.
- Updated frontend components to support new validation and push processes, including user feedback for validation results and progress tracking.
- Changed favicon to SVG format for better scalability and appearance.

backend/curve_client.py

@@ -0,0 +1,148 @@
+"""Luxsin 曲线 API：拉取、自定义 Base64 解码与 parametric_eq 校验。"""
+import base64
+import json
+import logging
+from typing import Any, Optional, Tuple
+from urllib.parse import urlencode
+
+import requests
+
+logger = logging.getLogger(__name__)
+
+LUXSIN_CURVE_API_BASE = "https://api.luxsin.com.cn/audio/getCurve"
+
+CUSTOM_CHARS = "KLMPQRSTUVWXYZABCGHdefIJjkNOlmnopqrstuvwxyzabcghiDEF34501289+67/"
+STANDARD_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+
+TARGET_OVER_EAR = "Harman over-ear 2018"
+TARGET_IN_EAR = "Harman in-ear 2019"
+
+FORM_TARGET_MAP = {
+    "over-ear": TARGET_OVER_EAR,
+    "in-ear": TARGET_IN_EAR,
+}
+
+
+def curve_target_for_form(form: Optional[str]) -> Optional[str]:
+    if not form:
+        return None
+    return FORM_TARGET_MAP.get(form.strip().lower())
+
+
+def custom_base64_to_string(encoded: str) -> str:
+    """将 Luxsin 自定义 Base64 字母表映射为标准 Base64 后解码为 UTF-8 字符串。"""
+    if not encoded or not isinstance(encoded, str):
+        raise ValueError("曲线数据为空")
+
+    standard_b64 = []
+    for c in encoded:
+        idx = CUSTOM_CHARS.find(c)
+        if idx != -1:
+            standard_b64.append(STANDARD_CHARS[idx])
+        else:
+            standard_b64.append(c)
+
+    try:
+        raw = base64.b64decode("".join(standard_b64), validate=False)
+    except Exception as e:
+        raise ValueError(f"Base64 解码失败：{e}") from e
+
+    try:
+        return raw.decode("utf-8")
+    except UnicodeDecodeError as e:
+        raise ValueError(f"UTF-8 解码失败：{e}") from e
+
+
+def is_valid_parametric_eq_payload(data: Any) -> bool:
+    if not isinstance(data, dict):
+        return False
+    peq = data.get("parametric_eq")
+    if not isinstance(peq, dict):
+        return False
+    filters = peq.get("filters")
+    return isinstance(filters, list) and len(filters) == 10
+
+
+def extract_encoded_payload(response: requests.Response) -> str:
+    """从 getCurve 响应中提取待解码字符串。"""
+    text = (response.text or "").strip()
+    if not text:
+        raise ValueError("曲线接口响应为空")
+
+    try:
+        body = response.json()
+    except ValueError:
+        return text
+
+    if isinstance(body, str):
+        return body.strip()
+
+    if not isinstance(body, dict):
+        raise ValueError("曲线接口响应格式异常")
+
+    for key in ("data", "curve", "result", "content", "body"):
+        val = body.get(key)
+        if isinstance(val, str) and val.strip():
+            return val.strip()
+
+    nested = body.get("data")
+    if isinstance(nested, dict):
+        for key in ("curve", "data", "content", "encoded"):
+            val = nested.get(key)
+            if isinstance(val, str) and val.strip():
+                return val.strip()
+
+    if isinstance(nested, str) and nested.strip():
+        return nested.strip()
+
+    raise ValueError("曲线接口响应中未找到可解码数据")
+
+
+def fetch_and_validate_curve(
+    brand: str,
+    name: str,
+    form: str,
+    *,
+    timeout: float = 20.0,
+) -> Tuple[bool, str]:
+    """
+    拉取并校验曲线。返回 (是否通过, 失败原因)；通过时原因为空字符串。
+    """
+    brand = (brand or "").strip()
+    name = (name or "").strip()
+    if not brand or not name:
+        return False, "品牌名称或型号名称为空"
+
+    target = curve_target_for_form(form)
+    if not target:
+        return False, "佩戴方式须为入耳式(in-ear)或头戴式(over-ear)才能校验曲线"
+
+    query = urlencode({"brand": brand, "name": name, "target": target})
+    url = f"{LUXSIN_CURVE_API_BASE}?{query}"
+
+    try:
+        resp = requests.get(url, timeout=timeout)
+    except requests.RequestException as e:
+        logger.warning("getCurve request failed: %s %s", url, e)
+        return False, f"无法连接曲线接口：{e}"
+
+    if resp.status_code != 200:
+        return False, f"曲线接口返回 HTTP {resp.status_code}"
+
+    try:
+        encoded = extract_encoded_payload(resp)
+    except ValueError as e:
+        return False, str(e)
+
+    try:
+        decoded_text = custom_base64_to_string(encoded)
+        payload = json.loads(decoded_text)
+    except json.JSONDecodeError:
+        return False, "解码后的数据不是合法 JSON"
+    except ValueError as e:
+        return False, str(e)
+
+    if not is_valid_parametric_eq_payload(payload):
+        return False, "曲线数据异常"
+
+    return True, ""