Display number of new tests for subset and New column for inspect commands

[takanabe]

Background

We want to let the CLI users to know if tests are new and how many new tests are introduced for given subsets. This PR support the feature for subset and inspect commands.

Expected output

Subset command output with this change

We expect an output like below.

$ find ./tests/**/*.py | smart-tests subset file --session @session.txt --target 20% > subset.txt
Smart Tests created subset 410 for build  (test session 802) in workspace konboi/pts-v2

|           |   Candidates |   Estimated duration (%) |   Estimated duration (min) |
|-----------|--------------|--------------------------|----------------------------|
| Subset (New Tests) |           18 (3) |                    20.00 |          0.00 |
| Remainder          |               72 |                    80.00 |          0.00 |
|                    |                  |                          |               |
| Total              |               90 |                   100.00 |          0.00 |

Run `smart-tests inspect subset --subset-id 410` to view full subset details

(3) new test count in Subset (New Tests) | 18 (3) comes from summary.subset.newTestCount, which this branch added to JSSubsetSummary. The CLI reads that field to render the parenthetical.

Inspect command output with this change

We expect an output like below.

| # | Test                                      | In Subset | Density  | Duration| New    |
|---|-------------------------------------------|-----------|----------|---------|--------|
| 1 | src/test/java/com/example/FooTest.java    |   ✔       | ...      | 0.000s  | Yes    |
| 2 | src/test/java/com/example/BarTest.java    |   ✔       | ...      | 0.000s  | Yes    |
| 3 | src/test/java/com/example/KnownTest.java  |   ✔       | ...      | 1.230s  | No     |

The New column (Yes/No per test) is driven by numNewTests on each OptimizationResult in the inspect response. SubsetDetailService returns the full OptimizationResult objects including numNewTests, so the CLI can check numNewTests > 0 to render Yes/No.

local executions

Subset

Inspect

uv run smart-tests inspect subset --subset-id 7
|   Order | Test Path                                              | In Subset   |     Density | Duration   | New   |
|---------|--------------------------------------------------------|-------------|-------------|------------|-------|
|       1 | file=tests/commands/test_api_error.py                  | ✔           | 1800000.000 | 0.001s     | Yes   |
|       2 | file=tests/test_runners/test_googletest.py             | ✔           | 1800000.000 | 0.001s     | Yes   |
|       3 | file=tests/commands/record/__init__.py                 | ✔           | 1800000.000 | 0.001s     | Yes   |
|       4 | file=tests/test_runners/test_maven.py                  | ✔           | 1800000.000 | 0.001s     | Yes   |
|       5 | file=tests/commands/record/test_tests.py               | ✔           | 1800000.000 | 0.001s     | Yes   |
|       6 | file=tests/commands/test_verify.py                     | ✔           | 1800000.000 | 0.001s     | Yes   |