feat: 添加 API Key 锁定功能和请求头规则系统

1. API Key 锁定功能
- 管理员可锁定/解锁用户的 API Key
- 锁定后用户无法使用、修改或删除该 Key
- 前端显示锁定状态并禁用相关操作

2. 请求头规则系统
- 将 endpoint.headers 升级为 header_rules
- 支持 set（设置）、drop（删除）、rename（重命名）操作
- 前端提供可视化规则编辑界面
- 包含数据迁移脚本

Close #37 Close #86 Close #88

alembic/versions/20260115_2300_6d579000e511_add_header_rules_and_migrate_data.py

@@ -0,0 +1,102 @@
+"""add header_rules to provider_endpoints and is_locked to api_keys
+
+Revision ID: 6d579000e511
+Revises: e4ebe3233b40
+Create Date: 2026-01-15 23:00:00.000000+00:00
+
+变更:
+1. provider_endpoints 表: 添加 header_rules 字段，迁移 headers 数据
+2. api_keys 表: 添加 is_locked 字段（管理员锁定标志）
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import JSON
+
+# revision identifiers, used by Alembic.
+revision = '6d579000e511'
+down_revision = 'e4ebe3233b40'
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(connection, table: str, column: str) -> bool:
+    """检查列是否存在"""
+    result = connection.execute(
+        sa.text("""
+            SELECT 1 FROM information_schema.columns
+            WHERE table_name = :table AND column_name = :column
+        """),
+        {"table": table, "column": column}
+    )
+    return result.fetchone() is not None
+
+
+def upgrade() -> None:
+    """添加 header_rules 字段并迁移现有 headers 数据；添加 is_locked 字段"""
+    connection = op.get_bind()
+
+    # ========== provider_endpoints.header_rules ==========
+    # 1. 添加 header_rules 列（幂等）
+    if not _column_exists(connection, 'provider_endpoints', 'header_rules'):
+        op.add_column('provider_endpoints', sa.Column('header_rules', JSON, nullable=True))
+
+    # 2. 批量迁移：headers -> header_rules
+    # 使用纯 SQL 将 {"k1":"v1", "k2":"v2"} 转换为 [{"action":"set","key":"k1","value":"v1"}, ...]
+    if _column_exists(connection, 'provider_endpoints', 'headers'):
+        connection.execute(
+            sa.text("""
+                UPDATE provider_endpoints
+                SET header_rules = (
+                    SELECT jsonb_agg(
+                        jsonb_build_object('action', 'set', 'key', key, 'value', value)
+                    )
+                    FROM jsonb_each_text(headers::jsonb)
+                )
+                WHERE headers IS NOT NULL
+                  AND headers::text != '{}'
+                  AND header_rules IS NULL
+            """)
+        )
+
+        # 3. 删除旧列
+        op.drop_column('provider_endpoints', 'headers')
+
+    # ========== api_keys.is_locked ==========
+    if not _column_exists(connection, 'api_keys', 'is_locked'):
+        op.add_column(
+            'api_keys',
+            sa.Column('is_locked', sa.Boolean(), nullable=False, server_default='false')
+        )
+
+
+def downgrade() -> None:
+    """移除 header_rules 字段，恢复 headers 字段；移除 is_locked 字段"""
+    connection = op.get_bind()
+
+    # ========== api_keys.is_locked ==========
+    if _column_exists(connection, 'api_keys', 'is_locked'):
+        op.drop_column('api_keys', 'is_locked')
+
+    # ========== provider_endpoints.header_rules ==========
+    # 1. 添加 headers 列（幂等）
+    if not _column_exists(connection, 'provider_endpoints', 'headers'):
+        op.add_column('provider_endpoints', sa.Column('headers', JSON, nullable=True))
+
+    # 2. 批量迁移：header_rules -> headers（仅提取 set 操作）
+    if _column_exists(connection, 'provider_endpoints', 'header_rules'):
+        connection.execute(
+            sa.text("""
+                UPDATE provider_endpoints
+                SET headers = (
+                    SELECT jsonb_object_agg(rule->>'key', rule->>'value')
+                    FROM jsonb_array_elements(header_rules::jsonb) AS rule
+                    WHERE rule->>'action' = 'set'
+                      AND rule->>'key' IS NOT NULL
+                )
+                WHERE header_rules IS NOT NULL
+                  AND jsonb_array_length(header_rules::jsonb) > 0
+            """)
+        )
+
+        # 3. 删除 header_rules 列
+        op.drop_column('provider_endpoints', 'header_rules')