Sql dup colname bug (#631)

    feat: handle duplicate input column names across sql, sheet, and flatten

    A repeated header name previously crashed zsv sql (double-free/SIGABRT);
    it is now handled gracefully across commands:

    - sql: fix the double-free; add --rename-duplicate-columns to disambiguate
      repeats (a,b,a -> a,b,a_2); on a strict failure, emit an actionable
      parse-time error naming the column, its positions, and the remedy flag;
      note each rename on stderr.
    - sheet: sqlfilter and pivot disambiguate duplicate columns unconditionally
      (no flag surface) so such files stay filterable/viewable.
    - flatten: ensure unique output column names by default, noting renames on
      stderr.

    Build: add .d dependency tracking for the sheet unity build (edits to
    #included sources now trigger a rebuild); touch both utf8proc extraction
    outputs so the multi-target rule runs once.

    Tests: dupcol coverage for sql (crash/rename/error), flatten, and an
    interactive sheet sqlfilter test. Dedupe paths verified under AddressSanitizer.

    Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Fix issue introduced in a604594 (#604)

Count output (#601)

* count: add -o option
* configure: include -L in LDFLAGS_JQ

Add fast parser (#563)

* Performance optimizations
  * Faster scalar engine
  * Add `--parser fast` option to use faster CSV scanner for standard-quoted CSV
    * Available for NEON, SSE2 and AVX

* More robust tests
  - expanded test coverate
  - tmux tests more stable

* More robust benchmarking
  - verify correctness 
  - broader set of inputs
  - add qsv & xan
  - save platform-based results markdown

* Add make test-asan target

* Stabilize overwrite cleanup routines

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

add configure option to disable only-crlf support (#517)

2025 11 22 benchmark (#508)

* revert ZSV_SELECT_PARALLEL_BUFFER_SZ to 8MB
* update benchmark scripts

[CI] Dependencies cleanup (#505)

Update sheet.md

Update README.md

V1.0 rc1 (#425)

* sheet: add goto-column
* properly handle multiple quote chars after closing quote
* update README.md to include non-RFC-4180-complient examples