chore: add User-Agent header to Tailor Platform API requests

[dragon3]

This pull request adds User-Agent header to all HTTP requests to Tailor Platform API by extending the bearerTokenTransport to include user agent functionality.
The User-Agent format is patterner/<version> (e.g., patterner/0.8.0)

Changes

• Modified bearerTokenTransport struct to include userAgent field
• Updated RoundTrip method to set User-Agent header on outgoing requests
• User-Agent value is constructed from version.Name and version.Version

Motivation

Setting a proper User-Agent header helps with API request tracking, monitoring, and debugging on the server side. It allows the Tailor Platform to identify requests coming from the patterner tool and its version.

[github-actions]

Code Metrics Report

	main (c6f2e7e)	#49 (ef68456)	+/-
Coverage	27.5%	27.4%	-0.1%
Code to Test Ratio	1:1.4	1:1.4	-0.1
Test Execution Time	7s	7s	0s

Details

  |                     | main (c6f2e7e) | #49 (ef68456) |  +/-  |
  |---------------------|----------------|---------------|-------|
- | Coverage            |          27.5% |         27.4% | -0.1% |
  |   Files             |             12 |            12 |     0 |
  |   Lines             |            563 |           564 |    +1 |
  |   Covered           |            155 |           155 |     0 |
- | Code to Test Ratio  |          1:1.4 |         1:1.4 |  -0.1 |
  |   Code              |           1483 |          1488 |    +5 |
  |   Test              |           2178 |          2178 |     0 |
  | Test Execution Time |             7s |            7s |    0s |

Code coverage of files in pull request scope (53.8% → 50.0%)

Files	Coverage	+/-	Status
tailor/tailor.go	50.0%	-3.9%	modified

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Reported by octocov

[k1LoW]

LGTM! Thank you!!!