test: add 61 coverage tests and bump pyproject version to 1.2.0

[Coding-Dev-Tools]

Adds 61 comprehensive tests for JSONL, type widening, batch edge cases, and aligns pyproject version with release tag.

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[github-actions]

🤖 Automated Code Review

✅ Ruff Lint — No issues

⚠️ Ruff Format — Formatting needed

unformatted: File would be reformatted
  --> README.md:28:1
   |
27 | import pandas as pd
   - df = pd.read_csv('huge_file.csv')  # OOM on 5GB+
   - df.to_parquet('output.parquet')
28 +
29 + df = pd.read_csv("huge_file.csv")  # OOM on 5GB+
30 + df.to_parquet("output.parquet")
31 | ```
   |

unformatted: File would be reformatted
 --> conftest.py:2:1
  |
1 | """pytest configuration — add project src to Python path and skip rate limits."""
2 +
3 | import os
  |

unformatted: File would be reformatted
   --> src/datamorph/cli.py:103:15
    |
102 | @click.option("--pattern", default="*", help="File glob pattern (default: all files)")
    - @click.option(
    -     "--recursive", "-r", is_flag=True, help="Search subdirectories recursively"
    - )
103 + @click.option("--recursive", "-r", is_flag=True, help="Search subdirectories recursively")
104 | @click.option("--csv-delimiter", default=",", help="CSV delimiter")
--------------------------------------------------------------------------------

✅ Secret Detection — Clean

✅ Large Files — Within limits

📊 Diff Stats — 5 file(s) changed

 .github/workflows/ci.yml          |   2 +-
 .github/workflows/npm-publish.yml |  33 --
 .gitignore                        |   3 -
 pyproject.toml                    |   5 +-
 tests/test_coverage_gaps.py       | 685 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 687 insertions(+), 41 deletions(-)

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Verdict: ⚠️ Warnings — Lint/format issues found. Recommend fixing before merge.

Automated by Coding-Dev-Tools/.github reusable workflow.