date: support GNU-compatible out-of-range years and formatting parity

[abhishekpradhan]

Summary

• accept parse_datetime::ParsedDateTime::{InRange, Extended} in date -d flow
• add extended-year formatting path for out-of-range years with GNU-compatible output behavior
• fix timezone conversion for extended dates (-u, local TZ output, explicit input offsets)
• add support for additional format specifiers on extended dates, including week/year directives (%U, %W, %V, %G, %g)
• handle extended parse results in touch -d without panic
• add regression tests for large-year output, DST-aware IANA rules, and formatter parity

Dependency sequencing

• depends on parse_datetime PR: Groundwork: widen year parsing bounds for GNU max year parse_datetime#261
• this branch temporarily pins parse_datetime to that PR commit via git rev so CI can run end-to-end.
• once parse_datetime is merged and released, this should be switched back to crates.io dependency.

Related issues

• Date rejects valid large years that GNU date accepts #9774
• Large year values are not parsed correctly parse_datetime#160

Testing

• cargo check -q -p uu_date -p uu_touch
• cargo test -q --test tests test_date::test_large_year_with_explicit_offset_converts_to_output_timezone -- --nocapture
• cargo test -q --test tests test_date::test_large_year_supports_r_and_c_formats -- --nocapture
• cargo test -q --test tests test_date::test_large_year_iana_timezone_rule_uses_dst_in_far_future -- --nocapture
• cargo test -q --test tests test_date::test_large_year_week_format_specifiers -- --nocapture
• cargo test -q --test tests test_touch::test_touch_large_year_date_does_not_panic -- --nocapture

[abhishekpradhan]

Updated this branch to pin parse_datetime to the current top of the split stack:

• PR1 (upstream): Groundwork: widen year parsing bounds for GNU max year parse_datetime#261
• PR2 (stacked in fork): Add extended runtime + ParsedDateTime API for large years abhishekpradhan/parse_datetime#1
• PR3 (stacked in fork): Add large-year parity tests and README updates abhishekpradhan/parse_datetime#2

Current pinned SHA: 0a3b73f51d62e728d354d29bfedbafcf8c1731bd.

[codspeed-hq]

Merging this PR will improve performance by 3%

⚡ 1 improved benchmark
✅ 116 untouched benchmarks
⏩ 209 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	du_summarize_balanced_tree[(5, 4, 10)]	7 ms	6.8 ms	+3%

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_{Comparing abhishekpradhan:codex/large-year-date-parity (bb44ef6) with main (42e3ab6)²}

Footnotes

1. 209 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (def3956) during the generation of this report, so 42e3ab6 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩