feat(strm): custom path prefixes

[sevxn007]

Description / 描述

strm驱动路径前缀不再限制死为/d,支持自定义

Closes #1683 #1638

How Has This Been Tested? / 测试

Checklist / 检查清单

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[Copilot]

Pull request overview

This PR adds support for custom path prefixes in the strm driver, removing the hard-coded /d prefix and allowing users to configure it.

Key Changes:

• Added a new PathPrefix field to the strm driver configuration with a default value of /d
• Updated the path generation logic in getLink() to use the configurable PathPrefix instead of the hard-coded /d
• Bumped the driver version from 4 to 5 to handle migration of existing configurations to set the default /d prefix

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
drivers/strm/meta.go	Added new PathPrefix configuration field with default value /d to support custom path prefixes
drivers/strm/util.go	Updated getLink() method to use configurable PathPrefix instead of hard-coded /d prefix
drivers/strm/driver.go	Incremented version to 5 and added migration logic to set PathPrefix to /d for existing configurations

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