test: add optional pytest-benchmark suite for core operations

[acul71]

Summary

Closes #45.

• Add pytest-benchmark to [project.optional-dependencies].dev
• Add tests/test_benchmarks.py for Code, tag, prefix encode/decode, and known_codes
• Benchmarks are opt-in (--benchmark-only); not required in default CI tox core beyond collecting tests
• Add newsfragment 45.performance.rst

Demo

.......                                                                  [100%]

------------------------------------------------------------------------------------------------- benchmark: 7 tests ------------------------------------------------------------------------------------------------
Name (time in ns)                       Min                    Max                  Mean              StdDev                Median                IQR            Outliers  OPS (Kops/s)            Rounds  Iterations
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
test_bench_known_codes              62.9807 (1.0)       2,497.9818 (1.92)        73.8960 (1.0)       26.6111 (2.99)        71.0133 (1.0)       3.9581 (1.54)     620;1867   13,532.5237 (1.0)       16302           1
test_bench_code_construction        71.0315 (1.13)      1,399.3431 (1.08)        82.9965 (1.12)       8.8988 (1.0)         82.2201 (1.16)      2.5630 (1.0)    6595;12490   12,048.6981 (0.89)     199759          32
test_bench_extract_prefix          163.3106 (2.59)      1,301.0697 (1.0)        177.3419 (2.40)       9.0994 (1.02)       176.2428 (2.48)      5.1383 (2.00)    8177;6817    5,638.8238 (0.42)     194479          29
test_bench_get_codec               227.9994 (3.62)      3,490.0149 (2.68)       259.4296 (3.51)      43.3151 (4.87)       256.9868 (3.62)     23.0502 (8.99)    4195;4518    3,854.6102 (0.28)     157705           1
test_bench_add_prefix              249.0124 (3.95)     18,149.0323 (13.95)      277.9969 (3.76)      65.9678 (7.41)       273.9835 (3.86)     16.9966 (6.63)     851;9170    3,597.1618 (0.27)     174795           1
test_bench_code_from_string        582.0184 (9.24)      5,316.9788 (4.09)       642.5564 (8.70)      71.0837 (7.99)       636.0351 (8.96)     33.0037 (12.88)   3004;4775    1,556.2836 (0.12)     191646           1
test_bench_code_tag              1,075.9686 (17.08)    10,920.9795 (8.39)     1,200.6378 (16.25)    102.9081 (11.56)    1,191.9765 (16.79)    44.9363 (17.53)   2260;3860      832.8907 (0.06)     130056           1
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Legend:
  Outliers: 1 Standard Deviation from Mean; 1.5 IQR (InterQuartile Range) from 1st Quartile and 3rd Quartile.
  OPS: Operations Per Second, computed as 1 / Mean
7 passed in 2.81s

Test plan

• make lint / typecheck / test / docs-ci locally
• Newsfragment 45.performance.rst present
• CI green on this PR
• Review requested from @sumanjeet0012

Made with Cursor

[acul71]

@sumanjeet0012 Could you please review this PR when you have a chance? Thanks!